Beginning to learn Android - Acube - All About Android - Part 1 | Shwetank Sharma | Skillshare

Beginning to learn Android - Acube - All About Android - Part 1

Shwetank Sharma, Teacher at SkillShare.

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12 Lessons (1h 34m)
    • 1. Introduction to the Course

    • 2. Principles of OOP

    • 3. Discussing the first Code.

    • 4. Variables and DataTypes

    • 5. AcubeSS5

    • 6. AcubeSS6

    • 7. AcubeSS7

    • 8. AcubeSS8

    • 9. AcubeSS9

    • 10. AcubeSS10

    • 11. AcubeSS11

    • 12. AcubeSS12


About This Class

Concepts covered in this class are -

  1. Basics of Object Oriented Programming
  2. Variables and Data Types
  3. Class and Method
  4. A  ' Hello World ' Android App.

In this class, we will start learning Android from the Scratch !

Students are not supposed to know any basics of either Java or XML.

We start right from the very beginning ....

We will begin with understanding the principles of Object oriented programming.

Going forward, we will understand other important concepts of Java so that we can get prepared for Android Development.

The class ends with students learning how can they develop their first basic Android App. 

This is the first class of the All About Android - Acube series. Future classes of Acube series will utilize concepts taught in this class.

Lets get started !


1. Introduction to the Course: a cube all about Android. In this CDs off classes, we will learn android from scratch. And when I say from scratch, I mean it. No Presumptions from my side. You don't know anything about programming languages. You don't know anything about the android programming. Not nobody will cover it all. It's not now. What is enjoy Android is logic on design, walking together, who create something. Logic is Java and design is XML. I don't want to confuse you with job unacceptable heavy words. But believe it or not, these are very simple pumps, Java and excellent. That is all you need alone. Make android programming happen. Have a look at these figures. Let's say these are and a nose which can convene warp. Do you like the shape of these? Convertino's? Have a look at this one. Do you think it can contain water? Yes, it can, because if I pour in water from here, the water will be stored inside this container. Same applies to these two pillars as well. But if you were to keep water in these containers and put these containers on a table or on a flat surface, there are very good chances that the water will flow out. Or in fact, the containers will not be able to stay where they were placed. There will basically tumble down, right? Have a look at this? Convenient? No, A very simple convener, which looks fine. And you are pretty confident that if you put water in this container, the what will stay on to spend a never also be stable. You put it on a flat surface. This convey live is what signifies that you need alone when you do android programming, which is that anything that you design on anything that you make from in droid should be logical. It should be able to store water and a troll to look pleasing, confident it should look. It should give confidence. Toe the users off your android creation that whatever they are using is very swoop, and that's where the design part comes in. Let's move ahead. What is an object oriented language? Have you heard of this word? Object oriented language? Three words together, a language which deals with objects as simple as that I don't want to complicate it for you . It's very simple, an object. But even language is a language which deals with objects. Now there is something called procedure languages, languages that follow a series of steps like this I don't sign that follows a specific park . It shows that the barkers bound there. It starts here and it goes in this downward direction at what a procedural language does. An object oriented language also has a specific part, but it is not very particular about the part. Emphasis is on the objects that we come across in that part. And what do we do with those objects? An object oriented language. We also have parts like this. You know that you're going from here to here and then coming back from here to here. But the emphasis is going to be on these objects. There are three objects that you see on the screen right now, This one this one in this one. So when you do object oriented programming, you will be more interested in What is it better doing with the objects in your programming ? Off course part will play a white and roll, but you will be more interested in what happens to the objects that you create. And how did they work out for you. What is job? It is an object oriented language. Simple. All right, enough for now. See in the next class. 2. Principles of OOP: principles, off object, body and programming. No job has a structure. Everything has a structure. While most of the things do have a structure, the structure makes like Java one of the most used languages. Actually, the structure is derived from object oriented programming concept, and that's why job is so much used in our wars. Let's talk about these structures now. The principles that Joe has are abstraction. You pull your laptop lap or even a happy basically be like naming things. You don't call it a machine with plastic or metallic body that has microcontrollers chips. Barton's screen that can do Mark. Ask Eric. We like naming things, and we don't want to call them with such huge names. That's what abstraction is. We will call something by what it does real. Name it on our own inspection encapsulation. Switching on your laptop camera does not affect the music Appling music. We want things to keep walking independently off each other. We don't want a situation where you switch on a camera in your laptop while music is being played, music will play at maximum one do. You don't want the situation to come in right? So encapsulation makes sure that you, when you switch your laptop camera, has no defend the music Appling music. And if it does, the computer or your laptop informs you well in advance about it. That's in absolution. Inheritance. We like sharing stuff you can call your laptop computer as well. There are a lot of people who still called a laptop size computers because inherently laptop is nothing but a computer. The computer gives all its properties to lap, and we're finding this so headedness on polymorphism your laptop and play any music video. It does not matter which language isn't. We want things to work everywhere, right? So if you are using a calculator to calculate something, you will not like to have a calculate, which only calculates even numbers rod numbers. You want a calculator that works? Or a laptop that can play in this song's Spanish life performance videos per annum, right? That's partly more physical. All right, that I see you in the next class 3. Discussing the first Code.: All right, let's start boarding already. Yeah, White wait for something which is so simple and yet so important. This is a simple Java program. All this file 1st 1 door Java class 1st 1 public starting white mainspring on system Got parental and blood. A lot of line. A lot of stuff which you might not understand at all. Or if you have learned a little bit of programming you already understood this. But for the sake of those who have not read anything, I'll explain this. When I run this program, I get out with us. This is a simple Java program. So this is the output. This is what you get when you run this program. The simple program. And if you observe this is mentioned here. This is a simple Java program. So this program, extra responsibility on this board extra responsibility to bring this thing to the user. Simple is our program. Now let's observe this cold. There is an open race here. Close brace. Here. This is called open braces called close place Andi. Another set here. Open brace. Close. Praise. So what this really means is that this core is starting here and ending here. Right? And this part off the court is stopping here in India, right? As a programmer, it's your responsibility to remember that where the court begins and very times Now, when you call in the real world, you will not get these helping. You know these circles which will help you toe market the territory's off court. But you will have toe, you know, really figure it out on your own. So if I want to give you the situation, you can say that this opening race starts here and this will end here because this will. This thing has started there in danger because there is another part which starts here in into right. So at any point in time, you go warn who started board here and then here because then how will you end this part? Of course, this is a big ning and this is the end. This is a big name is the end. If I were to start here and India cared, then I will not be able to justify this. My gold starts here and into my court starts here and ends here In that case, this line of this part of the court is being shared by two different chords, which is not something that we won't. So how to help ourselves out in such situations? Well, the kind off programming tools that you have today. If you will bring your person toe one of these braces, it will automatically mark the other beginning or ending off the court so you don't have to worry about this on. In case you are, you are messing it up. You don't every year. If you're not, really, you know, taken care of these opening and curly braces, you will get errors, and you will understand that there is something wrong with the braces that I've put. Bubble slash double forward Slash is the president's comments anything after double slashes not read by the compiler? What is compiler? Compiler is a sort off worker which read your cord and does whatever your court wants the computer to do. All right, so the compile it or the war per off the computer will not read anything that is after the double slash Another example off something that is not being read by the compiler. Is this so anything that I right between the forward slash and a strict as frickin forward slash with Lord me that by the compiler great. An important thing that I want to mention here is that the compiler or the person who is working inside the computer for you will read the court from top to the bottom and left to the right. It is actually exactly the way you need anything, right? So if when the compiler comes and does the compiling for your board for this in this case it will not read this line because it will say Okay, I started here and then I found this. So until unless I get this, I will stop reading anything that is in between it all right Said the compiler will not read. This is a simple our program. This is for us. This is for the devil. Oppose so that they can mention for other developers to read this and understand why that this court has been written. We call this woman's basically now next talk about class. You saw this class here. This is a key word. I will not read about it right now. Will not discuss it right now. Too much will not get into it too much right now, but I want you to get introduced. This word, it's gonna come up a lot off aims, and very soon you'll become friends with this world. Class is an important concept that will disk assume for the finding you can consider plus, to be something inside which we will write our court so last for timing for you is something inside which you will be writing your court male now mean is a method. It is like a formula that you write to perform asks. So main here is a method maker is a formula which performs your masks. It can also begin puts in provide outputs like In this case, Maine is a matter and then it does this task for you to print out this line to the user, right? It can take things with it from the user or from the other things in the cord, and it can also not take things, so it is not a necessity. It is up to you, the developer and these inputs are Korda's arguments are barometers oblique. Another key work public means that this is available to everyone as the name suggests public it's available to everyone. Let's not get into details too much right now. Static started means that this can be called directly, without instance, creating anything. Now This is a bit of confusion that I've brought him. So never mind will understand this thing. But I want you to get ready with he's you know I want you to and get introduced. Just my name. Thes thumbs. No system. That old print Ellen is a redefined method. Remember, Method Maine is also a metal right, so this main is also method. Similarly, this is also maker. It's a pre defined method. It's already there inside the system. This is not something that you will create. It's already there inside the system. Let's see one more program, another program. This is the first race and this is the last place. So I will not make a mistake toe. Assume that this thing starts here and engine No, it does not. When I started this thing here when the compiler or when I have never read the scored, I will make sure that I find the right closing place for this opening race. So when I teach here, I realize that there is some other court which is residing inside the scored. And that's why this court is not ending here. This end belongs to this one. So basically, you can say that According when it is done, it has to make sure that the ending and the beginning is very rightly saved to each other again. You have mean here something that you already seem our class and then of static public, everything you've already seen. Now what is the output? This is X for in the value off eccentric who is 28? Let's see hard because this happens. So what happens is in the previous program, very printed just a simple line. We had this mean method, and here also we have another mean metal. So this mean method is going to perform a task in X acceptable to 14. We'll discuss what it is, but what I mean, you can understand this as a type on X is a wary about X is like an algebra. You've started as a round little bit off algebra. So it's a variable X is going to get used in this program on. We are introducing it here. Excessive below 14. Here we are providing a value to the way boo here. He told the compiler that the what kind off variable is this? And here we are giving a value to the medium. Now X represents 14 right system dot all parental and again the same thing. This is again a matter which is redefined on this matter. What it does is it prints Whatever the user has to be, show right. This is X and X. Anything that is inside the double courts will get printed as Attar's. If you remember, in our previous example, we had written something inside the courts, double courts and this double courts was, as it is given to the user, right. So this is what gets printed and that's why you can see this is X 14 right? And why do we have for him? Because we have written X here. So we want the user to see this line as it is, and we also want them to see this. And when you write this thing without double boots, the compiler will give the value of this so values for in because we have made accessible before, In here in the previous line So when the compiler comes here, the person who was working for you in court from here it says X is equal to 14. So people type Or rather, it will bring. This is X 14. All right, in the next line were saying X is going to extend to do so. What we have done is we are changing. The value affects from 14 toe 14 in to do, which is 28 now. This time, when you write system got out, print the value off X into the ways. Then what we're doing is we are printing the statement. As it is, the value of fake skin to do is. And after that, what happens is we are again printing systems or print Ellen X. Right. So this part, the value of fixing to do is has been getting printed here. I'm sorry for this small black thing that appears, but I can't help it. So the value of fixing to do is this comes from you, right? And then the next system that out print l and X takes responsibility. Toe print the value current value off Excellent, which is 28. One interesting thing which you will see here is that here I'm used print and here I've used print Ellen. So what happens is whenever you will use print Ellen the print Ellen we'll print whatever is given to it for getting printed. But it will also move the cursor or the printer with the next line. And that is the precise reason why when you printed this line, it got printed like this. This is exporting, and the Pemper was also moved for the next line. And that's why you see this thing came up in the next line because they use different Ellen . But in this case, we did not use print Helen. We just used pain and that that is the reason why when this line got executed by the compiler, when the compiler read this line and build what you object do. At that point in time, the print waas made at the same line as you can see the value of fixing to do is and then 28 off course. After the printer did it show up here. Then it went. It was taken to the next line. But we don't really care about that, because that is where our program. It's that's what it is about the second program that I wanted to discuss with you. If you have any doubts to let me know if you want any kind of discussion toe happen to let me know. One thing which I would like to share with you guys is that frankly, if you did not understand this thing in totality, it's OK if for you this these two programs were all about reading some random rooms, things on screen and you could not understand everything. It's OK. This is the first time you meet in these things and absolutely. And as we go forward, we're going to read and study and everything. Discuss everything that we saw here in one by one. So you don't have to worry if you did not understand anything. I just wanted you start seeing gold so that you don't feel left out or you don't feel surprised when you see the cords for the first time. All right. See you 4. Variables and DataTypes: All right, let's see what is awaiting a book and water data types. What is a medium? A piece off memory that can contain a value now in the computer on which you are going to pull your programming for laptop. Whatever that you're using has gotten memory inside it. And when you are running a program, you will be requiring memory so that you can store certain information which are important in the context of the program. Right? Let's say you wanted to a lot of calculation, like beaded in algebra, royal liver starting mats. During that calculation, you had a Buddha calculation in steps, and if you remember, like in algebra, you were first make X equal some value and then Eve. Easy work does a mother value. So these used to help you in getting to the final answer. Great. So in programming also, we have a concept called Variable. So variable is nothing, but he's off memory, in which we're going to store some kind of information. And then if we want to refer to that information, we will be using the name off that memory space that will be called variable. So when I write X is equal to 23 in a program. What really happens is that somewhere in the memory off the computer, there will be a number 23 which will be stored on the address or the reference off. That memory location will be provided by X. Next time, Whenever I want toe, use that number which is stored in the memory location. I will use X right. Similarly here. Also, I wanted to store 12.9 Andi, I stored it in the memory location and the name of that memory location is even now. So this is a provision in all the programming languages so that you can conduct calculations or do anything in steps and use these variables hasn't been required. Will name the memory slot, and that name will be called us. William. Now here, for example, in Texas school 98. I understand that has not yet been discussed, so you don't have to really worry about this, but let me exactly tell you what this statement means in this data. Now, X is a variable on the variable name or variable, and it has a detail. So all the way labels have some kind of leader time and basically means what kind of gate up do they represent? So it is in on what exactly is in we will see it been able. Name is X on value is Indian. Right? So in your program, if you want to have ah value off 98 stores because you want to use it later, you can use extra represent 98 x will be variable Name it. Will we deter Type on 19 will be the value. Now, Like we said earlier, Joe has did her types it a types type of data that you're dealing with. So if you wanted to start a number, you will use in. If you want to the store anything else, you will use the right data type for that. Whatever you want. The store every variable hasn't able did everybody will have a greater It is not possible for a burial not to have a type. The compiler or your own computer will start giving you enter before you could even run the program. If there's no data time for a variable because the computer wants to know what kind of data your story, this means that any variable that you be there must have its time, so make sure you have the pipe in place. Now, here are three examples. We have three variables here. Can you point out the variables here? So X is one variable. Why is another were able? And that is variable and their inner types respectively are in floor and yeah, we'll see. What exactly do they mean? I'm compatibility is definitely checked. Now, this is another thing that you need Blue. We will again discuss this as we proceed further, you cannot assume that every type will understand another. So what we really mean by this is that like you have already seen by now there are different types of data types that are available Your your we saw in float and now it is not necessary that care even understand what it means. What I mean to say is that if Zed's better type is there, then it might not understand What exactly is the value of X is holy right index is not compact moved away. So X, which is off typing is not compatible with add way. Let me explain this to you with examples as we go forward. Like I said, we will see this in actual leader. Nor did we learn this small lecture that every variable will have a data type variable helps you Oh, store some value in the memory on. Do you can use this Family and leader types might not be compatible with each other. See, in the next lecture and everything will be feel. 5. AcubeSS5: primitive bitter types in a previous election. We came to know back variables have later types. Now we will discuss primitive data types. There are other types of later tapes also, but we will understand them. They first we'll see primitive once you need clear with Peter tapes. Primitive year types Are these bip short in long? Yeah, Flute, Dublin and bullying. Bullying is my favorite, so I keep it for the end. And as you become more involved in developments, you will realize, Why do I say that bullying is my favorite? Here are the ages So the egg that we saw here are for the group in impeaches. So four of them, by short, in a long they are falling into the category off individuals that it goes is dad. Floating point numbers is flowed and double and bullion is bullying. So if you count these all at 18. Number 45678 right, So basically primitive later types have four subdivisions in page of characters floating point numbers in bullion. Now what exactly believe mean? First we'll talk about impede your group by. You will use this when you are working on very small later So let's see you decide that you need to use a variable X to store some value for your calculation on. Do you want to name the variables X So that is fine. Andi. You also know that you are working with very small early now. Very small. Bit up would mean that let's say you just want to store a very small number. Let's it, too, and you can use bite. They'll be viikii. Examples are by decks and bite right short. You will rarely use this data type. It is used to store small in ages. Another thing is before I discuss short, the permitted range is minus 1 28 1 27 4 bite. So all of these data types have gone a permitted range for bite. It's minus one contained to 1 27 So any number falling between these two is allowed will be stored as bite. Right now, let's come back to shore. Vomited ranges. Miners 3 to 7 succeed 3 to 767 Big range. It's a lot of large numbers can common on duh for any issues that has to be stored, which is falling in this feet. You can use short, but you you will rarely use it. As we go forward in this program, more you will realize we will. Hardly a talk about short examples would be short, excellent, short way in Now. This is while the most important, better types most used in our data type by dealing with numbers in Java. Vomited range, as you can see, is a huge range minus 21 for seven. So this is minus two billion something toe plus 1,000,000,000 something, right? So all the teachers which fall in the strange can be used with this data type again. The example were being excellent way right law before one from an Aegis group used winning is not able to store even larger numbers. So let's say you have a larger number larger than 2147 43 6 or seven. What would you do then? In that case, you will use hog vomited rangers minus to depart 63 toe dip are 63 minus one. Just imagine how huge this number is. In such cases, you use long examples again would be long eggs and love way. Now we have moved the second group, which is floating point numbers. You'll use floor to deal a day when you need to be with decimals, right, so basically procedure. So let's say you're dealing with a program you're writing a program who calculate acceleration off moving part. In that case, you cannot be a sure that the acceleration will come out in ages only made. It could also come in decimals. In such a case, you will use float so vomited ranges minus four e to depart minus zero for five. I told 3.4 e plus 0 +38 huge range on examples would be flow, Tex and float. Why double used when you need to deal with decimals again? But precision is high. So what I mean here is that Let's say you want to have a decimal, which is hey, which is having a lot off Essman places after the decimal point. In that case, you use double number legs. Double why examples? It has got a larger range than float on. Uh, you use it whenever you need to be decimals, which have high precision with them. Yeah, used when you need to deal with characters, what exactly do you mean? My characters well we could range is 0 65,005 26 Example will be addicts and Katwe. We're pulling magmatic causes that in Java and a lot of other languages you can have single characters which are coming for your usage with single courts. Right? We will see more about this as we start doing programming. So if you're understand characters right of its OK, but for timing, you can understand that there is more like a character which has God single courts. When it asked to be a single Gatica. So you finite e and then put it in single courts. It's a cat. Great. That's for Unicord. This is an exception I have made. Your guards are actually very important. Onda. We will see How do they really make sense then job environment. Now you won't write programs that are global. What we mean by that is that if my program is used by user in France, it would be awesome if they could get program outputs and French. I think that makes sense. Great. It's a fake. If a user would like to see our would like to use their mobile phone or their computers in French language. And my outputs should also be in France. French, right. Make this happen. We used cars so we will see. How does does this really happen when you go forward? But for timing you can understand that in Java we use Unicord for characters, for example you because characters is important, I have intolerable example You? Yes, it is a class Alfa. And then if you remember, there is this this thing you have already seen a couple of times. Prices, please. Public starting wide mean We will discuss this. We have already discussed it once will discuss it further later. Now, here, there Who? Garrick variables that I have a plan. They are one and and cat is the theater type God one is 88 carried to his wife with single course. As you can see, there is no There are no single courts here with a B. So what happens is when I print this thing system that out print on by print this then I will see car one and character. This should get printed as tears because we have seen earlier. Whenever something is in double courts, it should be printed as eaters and the second line systems or old print Delon care one plus double courts with space inside it. Plus CAC, Let's Your result. This program displays the following opens are won and got to ex species White. What is it? Easy. The reason is, when I printed this line, I said, God, one in cattle. So this card for international travel in car with colon here calling here. After that, the next line comes in system, nor a print Ellen and one plus space cattle. When Gavin was to be printed, the compiler or computer read found on the value that is stored with carbon variable and it founded to be 88. No care one is actually off can type. That is character type, so it is not goingto bring 88 there. What it will do is every time to find out. What is it that 88 is representing when it comes to characters. If you guys know anything about a sky chords, then this is related to that. If you don't know what that sky codes, no problem. Ask I or asking whatever your pronunciation is right now, what exactly is happening here is that every character. So in this case, X has the Unicord as 88. So when you print it care one, it shows it does not show the evaluated there. It rather shows the actual value which is behind this as a character which is X similarly here. Why is in single court so it wouldn't get printed as it is and that's what happened to you . So in a nutshell, like until you or I can clarify this thing in this way that whenever you will have a character or care type variable, it will bring as it is if it isn't single courts. Otherwise it will try to find out what value does this number hold on? That value will be printed right string. Now string is something which was not included when I was discussing the previous list with you off primitive better because it is not a primitive leader, but it's very important, so we will go through it briefly. String is a secret, off characters are likely, said earlier. Directors is what a single letter or anything which is singly present in single corpse when a rate six string X is equal to hello there, ex leader type or type of string. And this entire thing now is belongs to ex here. X is a variable which will contain hello there sequence of characters. All of these all of these individually our characters. So if you want to represent something which has got sequence of characters, you lose strength bullion. Ah, bullion is my favorite. Like I said earlier, it is used when you need to be logical values. The permitted range would be either true or false. So when we see a logical, what we mean is, if something can be either true or false, then you will Who's bullying example for three billion? Explain why So we learned that every video you will never deter get types defined. What kind of our news? Well, evil can hold hold data times my nor understand each other. This is something which we pride understanding In previous lecture Also here again, I am emphasizing this in the upcoming lectures you will actually get all the standard or do I mean by this 6. AcubeSS6: scoop variable. You can declare a variable in either. Yeah, you can Dictator really will anywhere in your program A variable defined inside a block is valid Inside the block only is something that you have to remember. You can declare it anywhere You can start using it anywhere But it will be valid only inside the block Where the variable waas lead What do we mean by this? As you can see, there are there Is this calibrates here in your right So this is a block block basically means any area which is inside opening calibrates and losing calibrates So this is a block area. So if you define a variable here then you can use their variable here only you cannot go outside the block and start expecting that compiler or computer will understand one this variable stands for So just to remember this thing in your mind, let me show you an example. What's happening here is that we have in If this this is the block starting here with curly brace ending you We have a very well f which is off the grid I've been which is equal to zero. So if has a value of zero and leader Limousine Frank painted. So this will get printed. It'll be no problems with this. But in case I tried toe print it like this, That is, if I tried toe access the variable. Or if I try toe, use the variable outside this curly brace because this Kali Bai starts here. Andrea, the block ends here. So if I try doing this, this won't work. You will get a better. In fact, even before you could run the program, this will show up as a layer. And the compiler will say that this is not something that I could allow you. Right? I'm conversion now, as we saw, there are different types in Java and there is something I'm conversion Also in Java it's disgusting. Different data types might but might not understand each other. I think this is the end time. I'm saying so. It's time that we, you know, start discussing this further. An invasion might understand the floor, but only to a certain extent. Now, you know, in Major is basically in our bite or short, but basically takes care of numbers. Right? But there should be no decimals in this right float is for decimals. So what I'm trying to say here is that in Asia might understand the float. An indigent can understand afloat, but only to a certain extent. Why only to a certain extent, because it teaches, do not understand decimals. They don't have decibels. So if I try to make use of wood in teacher and float together, then invasion might say. OK, I know that this is a number, but I will not appreciate the decimals in this. That's why I said Lou, to a certain extent, what a double might not understand a bite at all. All right, for that matter, even a Boolean and care would understand each other at all. Bullion is only two involves, and car can have any character single character, which is double single story single courts, and they might not understand it all each other at all. Automatic type conversion happens when destination type is bigger than sore state. Now, this is something important. So as we know that we have been seeing that all these dear times have God Rangers, so automatic time conversion would happen. There will be an automatic conversion that will happen in the back and you will have to make it happen If the destination times bigger than so state let me show you an example. Here you can see that is ah, I mean, material on We are bearing a variable a here made it I was in and for, in his words, the value us Now I write long BZ will wait on declaring a new variable here. The time is long and I'm making it equal to a So what will happen is they'll be automatic taken. Lose now in the previous light In the last statement, they said, or to my pick type conversion happens when estimation time is bigger than source time For here the destination time is B and sources be. And if you remember, longs Range was much larger, much bigger than any. So this will be a very good case or automatic conversion. What will happen here is be well, be able to take the value off and the value off even automatically. We've been working long automatic type conversion again. It's happening here for Lord season will be floats. Range is also much larger than any. So this type conversion would also happened. So now see will get the value off B, which in turn had the value off a on the value of sea will be 14.0. It will only see a this 14 14 b will also see there's 14 only, but see even say I'm afloat. I'm going to keep decimals in type. So if you are 14 I'm going to make you 14.0 on. Technically also, you know you don't have any problems with 14 being corn escorting when. Zero. There's nothing wrong in it. In fact, you just adding to see in tow, right? So what will be the output on this program? As you can see, we're printing in value A so in value and we get 14 long value for in Florida, really 14 point there's there should be no space here, So my back they should not have been any this much of space there too many spaces. So 14 40 14 boils right? As you didn't see in then long. The values are 14 14 but because I like a set float will say, I don't care what whatever number you are. I needed a similiar, so it will say 14.0 passing in combat memory tapes. What if you want to assign in value to abide variable So let's say you have a bite. Ex im in Indonesia value for him on Do you want to assign this in value? Go by variable. What happens then? Ah, bite has less capacity than an individual. So here the source is having larger capacity than the destination. What to do now? So typically, this is how you will do the typecasting in case the automatic typecasting is not possible. In this case, you cannot have automated typecasting happening on its own because the destination has lesser space less and range than the source. So this is how you will do it In expired by VIAS he will toe annex. So you put bite in parentis is and then you say. And now it is going to be represented by boy. I want to clarify this thing here. Once this thing happens, X is not at all impacted by this statement. It's only why this gets impacted. I think that's pretty killed, but I wanted toe, you know, Say it out again. Now truncation You do busting. Let me show you an example What do I mean by provocation? Truncation technically are in English. This truncation means second on something. Let's say you have a small court slip it Help in eyes will triple and double early. So we have a variable. I wasn't values too. Anybody better have his double. If I lose 3.3 now, I'm going costing here I is equal. Who wouldn't be on? But this is the same parent. This is which we saw in our previous leg. So what would happen is when I print this, then I will get values off I India three and 3.3. Let's see how did this happen? So in the execution reached here, it said that I need to print values off NPR And that's why this card printed and then live in comfort. The statement which said I need to print a value which is inside I I had a value off 3.3. I'm accosted within and store deny right so 3.3 when it will be type costed through end, it will drank it or remove the 0.3 and it will. Only the only three will be provided to why right and that's hope became you. But in the third statement systems are our print l and B be even got printed. Dean, In any case, AC 3.3 and these value has not changed. This is second time I'm emphasizing on this. Please try to understand that these values nor changing you it is just that we're using the s a variable here. The value of bs variable here on duh. That is how I is being provided its value. But that does not mean these values changing. And that's why when we printed this week or 3.3 Great. So what did we love? Scope off variable. How amiable will be allowed to be used only within the bloc, where it was declared otherwise. It will not be possible. Used variable inter types. I think this is the second or third lecture over. We are mentioning your types. We have learned that and I conversion. Now we're affair at these data types can be converted to another data types, depending on requirement. But there are certain requirements. Are there a certain kind of conditions that are there before we do any kind of type conversion? Great. Let's meet in our next lecture and see what is their in store for us. See you 7. AcubeSS7: It's strange to disclose these and on his way to organize things. It's like a list that you want to me. If I were to give you five items and ask, you use them in your program. You can use five different variables. Andi. Store those five items in both variables and start using both free items. There is something else or areas which can help you do that in a much more efficient way. So these other fire items that I've given you these are five. Addict goes a B C D, and I want you to use them in your program. You can look at this list in a either working of your er is older we But what you need to understand is that this is a one dimensional thing. Great. So this is one diamond shoot. A B C. D is one aim and shoot similar to this one is also one image. So we will see in future programs. How can you exactly start using at is when we get in we android development, but for finding you can understand that there is some people lies which can help you organize things and make your programs look better. So what? You just what you saw just now was one diamonds, laddie. We can also have a day with food. I'm in shoes. Make this. So if I give you these many character 16 and number and I ask you deal with them in your programs you can have 16 variables and then put use the 16 variables of leader on store All of these different characters in those variables. But you can also use to diamond still, laddie, When they use these areas, you will understand much better. One thing which I want you to remember is that when you're dealing with, that is you build with their index. So let's say this area is named as alphabet. And if I want to ask you what is that zero element you will see it's a at his index works from zero. So it starts from zero in it cause in the number is required. So there are five items here. 01234 right? And that's how at his work. And now let's get classy. It's aimed introduced glasses. See you in the next picture 8. AcubeSS8: Thus, the class is a blueprint often idea that you won't work with the blueprint. Actually, here is a blueprint off our Let's say you want to make cars and here's the part. This is a blueprint of the car. You can use this blueprint to give an idea. What is it that you want to make so like, if I want to make a car and I want to end somebody that I want to make something, then I can make a picture off a car. It will have wheels. I can tell them that there are more reels, which you are not seeing right now. It is going to be a metallic structure. It is gonna have glasses. And of course I can use certain adaptations or some marks here to tell what exactly each and every part of this card is all about. That would be a blueprint, right? I have not actually made a car. Have just created a blueprint. The blueprint. You can give some properties. Like I said, you can say what color the parties. What is the name of the car? What is the engine part of the garden to these properties? Will also be given with this blueprint, Name, color and engine bar are properties of the class. You can also call them rebukes. No, I'm sure you have seen this class world a lot of places, right? So this is what it iss This is now the time when we will discuss what exactly a glasses last. Like I said earlier is a blueprint. So I decide that I'm going toe make a blueprint of the car in my programming language. In this case, it's shopper. So I God the name off the class, which is actually a blueprint. And then I will write name, color, an angel bar. These are sort off variables. These are actually variables only. But here they have more significance than just being a simple variable. These are attributes. These are the same attributes name, color, engine, part Victory. Found out why we were deciding upon the blueprint of the car. And we have named those attributes. Has your string name strain color learning in jobar? We know that name is well, who have chosen it, right? So named Nettie fits BMW. Then it's called Have not off characters in it. I cannot use ad for that because they're going to be more than one character. Axel can really support one, so I'm going to use string. String is nothing but a string of characters pub bunch of characters together. Similarly, color color is also going to be a world which cannot be taken care off by a character or car data type. So I'm going to use string here, an engine part like in this case, we're going to use only the number off the the number that the North stage in part right And this number is, let's say, is not going to be a similar to be on indigent only. So I have used in as data type. Here is the plus car that represents the entire blueprint. Another example. Travel destination. Let's say you want to open up a company which deals with travel. You are a traveler agent. You want open a company, and for that you want to make a plus. You want to prepare a software which can in with your business requirements, so you have probably destination as your business case. How do you make glass for travel destination? Any guesses? Well, the best way to make a class for anything is to think about that in our concept, in terms off its attributes, in terms of its properties. That course like in this case, we can say that anybody who wants to travel will travel to some kind of place which will have a name. So we have string and name that particular place will have poured, are in court, depending upon the geography that you are living in. So we, because it's US technologies, are most of the times accepted most of the cases, so I've used and record so in. ZIP codes are always pin numbers, so we'll write in support and country courts. Countries also have courts, the calling numbers off country. Every country has the record on because these two are going to be an intentionally I'm going to put in as the data types. That's the class for travel. Destination books are books. In terms of books. We can see that string name. So I know that the book is gonna have a name. So I'll use name as one of the properties on get state are type. I'm gonna keep a string, and every book has number of pages, which is going to be an issue type only, which is pretty sure because you cannot have a similar number of pages. So we're gonna pipe. Are we going right in as either for a number of pages Now you might wonder if I have I put on a book here. The reason is that you know, as we are progressing forward in terms off requirements in businesses were record realizing that e books are making their way in tow the markets. So your software good thing about your software or your class will be It will be happily, even the board these cases. And that's the beauty off programs. Another reason why I introduced any book heirs or whenever you write a program or anywhere you design a software. Always remember, you should be able tow, encapsulate are you should be able to consider all the cases that are there in your business requirement. Like this class. It can be used in both of these cases. Be the hard bone book paperback or be Beetle e book. It works in both the cases right off course you can. You can mention here another attribute, which is Is it off? Is it in a book or not on any guesses. What will be the data type for that? Well, it will be bullion if I write bullion e book or not, there can be only two cases. True or false. So it is best if I keep bullion as a stereotype. Of course I can have yes or no As to cases. In that case, I might choose care. But like I said, bullion is something which is the best application off any case, you will realize this as you go for further so in programming as much as it is possible. Tribal Keep things in bullion Now what blue with this blue plane? Another interesting question. We will now make objects from this will bring. See you in the next lecture. 9. AcubeSS9: Like I said at the end of the last lecture, we're going to make objects from the blueprint. That is how you will start realizing how important object oriented programming is to this world. Father, like we saw in our previous lecture, is a plus. So this is actually the way you make up checks off off blue brain. This is a last name of the glass. See, is the name of the object So C is going to be new of the object. New is keyword usedto create objects. You will need this keyboard. Now this is something new car. The new is actually knew that is being introduced here. So this is a keyboard. And there are a lot of other people in Java and other programming languages that people keep pampering and we will keep just handing them. But for now, this is the 1st 1 new. So new is a key word that you need and part with an emphasis is a ghost. Now this thing can look like a maker, but it's not maker. Technically, you man expected to behave like a member, but it's normal for acceptance. It is like a method, but it has certain privileges that in boys instructed, as the name suggests, is used. Hooper's front objects R C is equal to new bar, and after the statement, your compiler knows that there is an object formed, which is off the name. See why do we need the dealer? New. The beard objects instances of the class. This is the little This is little different than how you initialize. An important Now you can say that if I were to store value of five in X variable that you can write in X is equal to five and like and I know just simply died. R C is incredible. Let's say you know something like the properties or written on these properties can go directly in this object when it doesn't work like that. So this is the only way you can create an object. Off course. There are different radiation, slight variations off this method, which we will see in future. But this is the value will create an object. It is a little different than just initializing a variable with some value last clear to neuter. Yeah, that's very impressed Anything. So you already know that there are data types. We ask teddy bear types of them. So every time you create the plus, you are actually creating a different right. So in this example, R. C. So if I were to ask you what is the type of this object see, you will say part free Now what happens after this tape landscape executed after this statement? Get things he kilted. What happens is let's say this is the memory off your computer and the moment this statement gets executed, there is this object getting created, which is marked C one. It will have all the properties inside it or, rather, is ready to accept the properties off a car because it is an object off guard Plus. And these properties can be these three properties. If you remember, we have already seen these properties when we were discussing the blueprint off a car. So now whenever this statement gets executed, see, one is marked as an object and that basically prepares the compiler on the computer to make way or make some memory available for this object on In this memory space, the computer is ready to store the properties exact properties. These three properties off this object up and allow these properties are not have not been given to this object. But the computer knows that there are three properties that are going to be given to this object. Now. What happens if I write? Garci? Bouza, will you see one? In that case, you will say See you bitter babe off Sito is what? And then I even see one. Please notice that I'm not students knew. See new party like in previous kids when I was defining this object. So see who is not actually new or please see who is nothing but off reference which is pointing to the same object which we have defined earlier. It's not a new object. A new object is created only when I use the Cheever new. This is something very important than it has a lot off, you know, applications in Java and Android and a lot of other languages. So you have to understand this thing. If I right guard c two to C one, C two will say OK, I'm a reference off this Stephen object. I am not an object in itself. In just horns are the address off this memory location. It can only help you point toe the same object that was created in previous statement. It is not a new object because we did not use a new keyboard eo the same thing. You did not create a new object. In this case. You created a new reference off jobs. It's time to get the particle methods. Let's do this in our next lecture. 10. AcubeSS10: Mitchard's. Once you do things in a simple way, that is how I look at concept of members. If you know that you have to do something and you have to repetitively doing it, you should use methods. Now here's an example of a medical. If you remember you've already discussed Medford were in Riedel Public Stack. Avoid mean, and I said Maine is a matter, so that is also mentored, and pink color is also method. Whenever method will be used, you wouldn't see parentis is after the name of the matter. It might been in certain other things as well, but for not I'm being we will only look at a simple record. It does not have anything between the parentis is so you have a matter via the name of the Metro, this print color, and it also has a places. Block starts here in names here, so this basically means that the men third starts here and angel inside the metal. You have these statements, so students are out card print telling the task off. This statement is toe bring whatever is there in the double courts as it is on the task off this print is toe print. Whatever it is there which color is holy Now I know it might be a little confusing, but let me explain it to you again. So what is really happening here is that once the method gets executed, once the method is around then this statement gets executed or gets printed as it is. That's why you see there is this Sorry. There is this color off the arteries so you will get distinct winter Naspers. I am not put Oh, poor care. What is output going to be part? It's gonna be like this. Only a left off the artist on In the next line, you will have anything which is there inside this color. Did you? How do I know it's a lot to go because the class are is mentioned here. So I know that my class car has got three attributes name, color and Angel Bob the leader type off for engine power isn't And these two have spring as a waiter types. So if I like color here, whatever color is there for a particular object will get printed Here. Let me show you an example. Now, here you have Ah, blast on. You can see that this is the same class that you have been dealing with the low. But there's a slight variation here. More variation. Rather addition. Do you have three attributes? If I were to ask, you describe this car blasphemy you and say it has got three attributes Name an engine power in the tapes as Prince bringing in. And this class also has metal indicted Wrinkle. Right. I want you to understand that this is where the class card starts. And this is very strange. Not this. This is the place. So the way it works is anything which is there inside this car class belongs to this class , right? So we have three attributes here, and then a matter also is there. So this method starts here. Any names? Here We have some stool statements written here on these are the same statement that we have seen in our previous light. Now, here in this section, you see, there's another plus card execution and we have public static wide mean welcome back. So this is again a matter. This is a system matter. This is already there in the system and you cannot use it By changing it, you have to use it as eaters, right? So the name of the method is mean on like you can see. It also has a parent. This is starting here and ending here. But there is something written inside it. Even see to it later. We never quiet what exactly this means and it will be required. All right. So you have opening this year and ailing grace here. So the matter main matter starts here, and names were similarly you have the class card exhibitions starting year ending and ending here. Now, as you can see in the first this method. So let me tell you something. Whenever this main method gets executed, the entire matter will get executed off course. Right. So what happens in the first line of execution is that the computer? What it does is another compiler. It creates an object. We already seen this right. So there's an object creator which is represented by seyval. Right there is in the memory that is so space allocated for this object. And this object is getting their friends to see one in the next lane. You have C one Norton name. Is he will be so C. One is the object and there is this dot This is called his daughter operator. Dot operator Takes care off, attaching anything that is relevant. Toe this object here, right? So because it's an object off car class and we know what it has got attributes you can write Stephen dot name. Name is the first attributes, and because of the type of spring you can write Beetle here, right, it's in double courts on you can give the name be in the second line. You're giving another act tribute your now please understand You are mentioning the attributes Here in the second line you're saying OK, my objects colors will be blue and that's hope it is mentioned You the hardline You're saying OK, my engine part is gonna be 1 50 Let's it's how horse part and it's implicit that it's gonna be hard. Spar. So you say Okay, this blue beetle has got 1 50 or spark because extender diapers in. You can write 1 50 here, and then you are writing C one dot print color. So this means that in these three statements I call or rather I seeked these attributes and give them them some value in the food line. I'm saying call this method run This myth heard for this object object name is C one on different color is a method that belongs to the same class to which this object belongs. And that's why this method will run properly. So the moment this main matter gets executed, it will say Okay, First, let me create an object off car class car classes available here. Onda off course. One thing is that this is something which we will see in actual later that you You have to ensure that these two files are close by. What it means is that you know, they have to be either in the same package or same foreigner. I don't want to do think too much about it, but for timing you can understand that these two files have to be reachable to each other. Please, This one has to be reachable. Go this way. Otherwise, how will the main met heard make an object remain matter will say I don't know what the car is, right. So you have to make sure it's reachable toe this class. So here. What happened is after you gave attributes to this object. You said I know that there is the sprint color matter which is available toe this class car . So please execute this matter. And that's what Compiler did compilers said. Yes, of course. I can see there is a method here and I will. I'm happy to implement. Take a rather not implemented executed implementation is this you implemented it here and then the executor it you. So what will happen is after these three lines, you will reach your the compiler with creature. And it will run back to this print color and execute these two nights. And that's how you get system that out. Print Ellen, color of the car is proof, right? Uh, any mistake that you can see here in the output. Well, the mistake is that there should have bean blue should be the next line because there are open. Tell him So once this statement got executed, this line should be changed to next line and blue should be printed in the next life and how blue gets printed. The blue gray gets printed because when it reached here the execution reached here, it said that I am expected to bring the value of this color attribute on because you have called a metal on this object. See one on you wanted given a color to it. That's why Blue got treated, right? This is a very important thing that you have to realize. If you did not get it, I would advise. You can watch this lecture again. If again, you would not understand it. I'm more than happy toe. You know, actually, make another lecture on this. It's a very, very important thing. An object oriented language. You have to understand this, right? So assuming that they were destroyed desk you can move forward. Otherwise re watch this lecture. You don't get it. Put it on common sections. Let me know in your are you know and discussion forum here on. Let me know if I can help you in any other way. I know we start learning android break he has enjoyed. Let's deal with this next picture. See you 11. AcubeSS11: All right, Amos Company, start hoping an android films We will allow making in app display some next on an android for yes, you're going to do now on what all will be need So what all do you need here? If you remember in the first or second lecture that we started with we bummed about Android requiring who kind of finds a job file in an XML file tried So these are the who finds that you will need We have a lonely, probable Java part Nothing has been probable XML but believe it or not example is actually so simple that you don't really need separate course for it Or, you know, like you can learn it as you go forward learning in Troy. Of course I will. I will keep insured that everything that we discuss regarding XML is properly explained a text you plus and text with a plus. Now I'm sure you know what the classes Onda text for you is a class which has already be made by android developers on given to us to be used as simple as that. Any guesses how many lines are there in this class? So if you remember in car Plus we had approximately 10 lines. Any guesses? How many lines are there in text to class guessing Or you can of course, Google it. And I'm sure you will be stunned to know the answer on DATs Why? You know, I really appreciate Android down because the moment before they're put in, but it's a huge number. So what? All we need these are the four things that we need. What is a widget, which it is If you are on Enright for news or, you know, or you might know what is rich. It is, as you know, the you can create rejects in your enjoyed former TV. In order an average use are already not you. Basically, you don't know what a midget is. I will explain it to you. Nobody ajumma file to hold a logical Corp So you have. You know that, you know logic has taken care of by Java on. You will need this find so that you can take care of the logic now in this app that we're going to make. It's just a simple extra everyone displayed there. So you might wonder, what is the logic that is quiet there. Well, I would say the only logic is that you need a shower file. And just because you have a job file the logic art is being taken. Care off. But, you know, and forward going forward, we will make absolutely required Lord of Logical stuff. And that is where you really realize what you know. Amazing thing, Joe wise for you in Android. On an example. Find toe. Hold the Leo. What is it, Leo? Layout is for timing. You can understand layout. There's nothing bark, anything that is going to show up on the screen. It has to be represented, and it is represented by a layup to an XML file. The layout is, let's say, what is the layout layout is if I were to ask you, Can you describe the layout off this clean current screen? You can see there is a text, which is which is there a lot of Texas there on It is aligned like this and you have some Aramark CIA and then you will say that is text, which has some of the text has got this shape here and saw the text has gone adul shape here. So that's what really out There's layout is as in English term, You know, if you have if you know what the layout means in English. That is exactly what layout means here. Also a text you class to enable us to show text. So this class will basically have lot of attributes and methods that let you do what you want to do, which is actually showing text on the screen. This will be inside the jar file, of course. You know, like the Java file is there. Ondas our file will have this texture class implementation which we will see as we go into Android Studio takes two widget to enable us to show text in the layup. Now, you might be wondering right now Like you know, we have already talked about next class which is going to take care of chewing the text. And why do we need this widget? Just hold on. Hold your horses when we enter and white studio, you will understand. What am I talking about on like this? Like I said earlier, this would be part of the XML file. So the switch, it will be part of that excellent fight. So, uh, let us go on and temper Enjoyed Studio next sexual to see you 12. AcubeSS12: All right. Welcome to Android Studio. Uh, if this is the first time you have come to Android studio welcome you again on if you have already seen a little bit off Android studio by some means. Great. Welcome. You also. Now we're going to talk about Android studio right now with with requirement that we have in our hands. What we need to do is we need to display some next on an android phone. Whatever is required. Triple Dad will be discussing it first on as we go ahead and start making more APS, you will keep learning newer stuff which will comprise off learning your stuff for both XML and Java. And of course, things which are being provided by in droid libraries or buses or methods will also be discussed. Right? So let's go ahead and start discussing this stuff. But before that, I want oh, increase the size off this text. And how do we do that? I went to file and I picked on e Saudi settings. And here is the size I wouldn't make good name in. Yeah, this is I think this is fine or 20. Yeah, twenties. Okay, now we have a bigger screen. Andi. Sorry. Bigger form. And we will be in a better position to discuss stuff. First things first. I understand this is the first time you are actually, you know, inside Android Studio are we have not really. Because a lot of a lot of things which are there in Java, an XML in android. And you might feel paranoid that how I will understand all of this. So that is what I'm saying. The one who discovered Cherry 11 waas and as we go forward gradually will understand each and everything right now coming through this place. This is main activity, nor Java. Right? So this is actually a class trip. Emery on Google Glass. So this is a class. What is public. We briefly this positive earlier. But now we will not discuss it. Are less is quite fully discussed on it will be required later. But not right now. Classes this on. Name off. The classes mean activity, right? Vialli was making this project. I could have chosen, you know, change this in activity name, but I did not. So this is the name off my class. Meaning? Don't worry about extends on this Apcom activity. This looks like some kind off rocket times, although it is not. But still, we're not going to discuss it right now. Here is the first off early brace that you see here and where does it end now? As you can see, if you're using a good integrated development environment, that is what enjoyed studio is there's in shorter this Carla's I d. E. So if you're using ah board idea integrated development environment, then you will get these facilities which come very handy. Let me tell you, you know, when you make bigger projects, it will be very for you, you know, understand? Where is this this stuff Starting and wear this stuff killing. Right. So this is how it will help you. As you can see, it got blue, right? This is a class and on create is a method, right? So see, learning android is nothing but knowing what is Java and what is XML on how android has made use off both these things so as to make you or help you make awesome maps. So I think that's a That's a very great thing. I've just said so I'm writing home learning in Droid is nothing but knowing Java and XML and using Let me put double strokes here so that it still is a common in droids. Bieber stuff. Let me know. I did stuff only you make. Awesome APs. So now why did we you know why did why did I see that just when I was discussing all paid on be It is, like I said is a method right on on greed method. Like in our previous case, when we were talking about our part loss and they had the mid third inside it, we had defined that letter inside the class. In this case, we don't have to define the matter. This is already there inside Android on. I just need to use it. If I won't use it, I don't really have to define it. I don't have to paper on what exactly? On create is gonna go on create already knows its implementation. And it is their resigning inside the android SdK software development kit. Another thing that you will realize what exactly misty case, but for I mean, you can understand there's decays like a huge you for knowledge is card like a lot off glasses. Bieber incited these classes. Like when I said you should know Jiao an X symbol on use Androids be build stuff, make awesome maps. So that's what I meant. You know, on create is already meet. You don't have really make it. And that's how uh, this thing looks. So now we have we have medical, which is having open parenthesis CEO and then closing one here, and we have something inside it. We have not yet discussed anything about what goes inside invited to go inside. But for I mean, I can tell you that. You know, this thing acts more like an input, right? So it's more like an import that you provide with the method so that it can give you an outward. That's what is happening. You. So we're providing it with an input. And then we have another thing. Your supermodel create more worry about this. Forget it. Nothing discussing right now and then we have said corn in view, said content view is another matter. It's another matter, So you have a metal inside which you are using another method, and you are using our daughter, Leigh Outdoor Woodley, in the scope me now, Like I said said, Contrary views, another matter and we are providing it. Another important we provided one propio on and inside the apprentices. And here again I'm providing another input. Our bodily are Actually it's called mean, not nobody if you don't really get what all this is because we will talk about later. But for I mean you can understand that food in the school mean is nothing but the excitement. It's the actual file one which is responsible for showing the layout for showing the, you know, for, for for taking, care off anything that you want to actually show up on the screen. So this is what actually in this call means on duh. Where is it? It's you. And here, as you can see, activity in the school may not. XML is present on here it is this XML, which is for the first time you're seeing so I don't want you get paranoid at all. It's a very straightforward thing. Gradually, even at this time, I'm in again, we'll discuss it. So for timing, you will understand that there is this layout. It's a lini early out. What exactly this means that something will discuss later. It starts here and ends here. As you can see, the ideas and his has held us. Who realized Where does it start? So just sleep on this and it will show you where it names became. And we have lot off mambo Jumbo. And here you have to deal with this right now. But we have this extra here. What does this takes? Few. This extra you is over. Jake, remember I said we'll alternate require a widget. So this is what this which is on again I will say Don't worry about these two things will only talk about this right now. So this is hello world that has been returning her exes. Hello world want you write this now you can be. What you have basically done is you have completely We are asking XML. So you said Okay. I'm going to make an XML where I will have a layer and then inside that Leo time have a widget on this widget. I will l a widget who write hello world wherever it is displayed. And after that we'll go back to me and actively door java and now you can and try understanding what is really happening here, This method said on interview and providing off on an XML which is actually holding that reject that I want to display. Right. So it's like this method buzz a huge, huge roll off in your Java and XML. That's how I look at it. This matter is one of the most important med cards which basically connect your gel off I with your excitement you give this XML like this are hardly outdoor activity in this come in like input on. But this basically insures this matter. If you were to ask me what is the output of this matter? The output has it lets you connect the jar file wherever is written with the quite excellent right now because this is done. Now, let me just run this app when I say run this up. This means that I'm actually going to run this on an android device or and commuted. What is an android device? You already know it's an android phone art for finding. I will plan it on an emulator because I want you to see an emitter on. So it's gonna come very handy. Even you huge projects. And you can't run your abs every time on an android device. So first I'll run it on. Emily, how do you run an emulator? You might not have this thing right now in your android studio, because if in case you're just in started, you might not have the devices showing up here, But I already have. So once this thing finishes, I will see my devices right up here. And here they are. As you can see, there is a pick till nexus five X and on the Nexus s as well. Right. So I'm gonna choose this one on. Duh. Okay. Now, when? Sometimes we will see my device getting launched on, we will be able to walk on it like as if we were working on a really phone. There you go. As you can see, my emulator is ready. Andi, I have my up getting the spirit on my emulator. This is the X that I was trying to show you Hello, world. And the next is coming from this widget which is inside duty on the score Main door XML, This widget name is extra view and this maximal is able to present itself on the screen because off this method said content view and that's it. So this is how you saw that we, you know, we began from the scratch Onda we kept on going on and on until unless we are able toe, you know, understand how to display a small text Are any text on the screen? So that's it for my in. I would request you to join me in the next class which is gonna come up very soon, which is or probably it might already be there. When you look around on on and find that it's already dead in that class, we will take this to the next level. Where in civil understanding More about job. Our XML I android libraries, right? There's one thing which I want to leave you with. Please attend the or other, submit your your project that is available on Skill Share project Forum up. I have put in small questions there which you would like to answer and, you know, answered them on the forum which is common to everybody. People can share their ideas, people can. It asked the questions. People also get to understand each other's point of view, which is very important while you're learning anything, right? So that's it. Our little Then until the time we are back with our second class. Take care. And Bob, I see you.