Learn Flowcharts and Pseudocode from Scratch

1. Introduction: Hi friends, My name is obeyed Qazi, and today I'm gonna teach you about flowcharts and pseudocode from scratch, which means I will teach you from basics to advance. So let's see what do we learn in this course? You will learn about flowcharts and pseudocode. Why is it useful? What was it mean purpose in programming language? Okay, so once you're done, Let's dance flowcharts and pseudocode. You will easily understand any programming language because it builds logic. Okay, To understand programming language. Okay, so let's see what you will learn in this flowchart. You will learn how to solve the problems. Using flowchart. You will be able to identify the symbols in flowchart. Flowcharts have many symbols. I will teach you about each and every symbol. In subsequent chapters. You will know how, you will know which tools we'll be using problem-solving. You will learn about the lipid adding processing flowchart, you're repeating process means for loops, while loops repeat until loop, important in flowchart. Okay, so let's see what you will learn in pseudocode. You will learn how to solve arithmetic problems using the pseudocode. You will know how to use operators in pseudocode. Pseudocode has three main operators. That is arithmetic operators, relational operators and logical operators. You will know what is algorithm and you will know how to use a medial variables and constants in pseudocode. You will identify. You will be able to identify or define datatypes in pseudocode. So before we actually start writing a program, we need to drive the procedure to solve the problem. There are v is available to drive a solution to a given problem, such as flowcharts and pseudocode. Let's see what is the flow time. Flow chart is a graphical representation of the steps to be taken. Or you can say, steps to be followed for solving a problem. It consists of a set of symbols. Each symbol represents a specific activity. For example, I have drawn a flowchart. To show you an example of the flowchart, we see the first symbol is called. Let's start simple. It's very important in flowchart. So if this symbol is not there in your flowchart, then a flowchart is incomplete. Okay? This symbol is called input symbol. Okay? It accept the number from the user. Okay? Now the third, or we can say fourth symbol is called as processing. Similarly, nepal example, you want to accept the two numbers and then you want to add two numbers, right? Okay. Then you want to add two numbers. Your antigen will be done in processing symbol. Display output. We will use outputs in. This symbol is called as stock symbol, keep, Remember stop symbol and start symbol. Both are seen and both are very important in the flowchart. Let's see some advantages of flowcharts. Flowcharts and analyzing the problem effectively. The flowchart as a guide during the program development phase. Flowchart helps easy debugging of logical programs, or you can say logical errors. The flowcharts helps in mentoring programs. Well, let's see what you will learn in pseudocode. Pseudocode is a comprehensive depiction of the solution to the problem and provide programmers detailed template for writing instructions in a specific programming language. So for example, you want to write the program in C, C plus, plus C-Sharp or Java or any other programming language, okay? Then you must write pseudocode for the program. It will become much easier to write a program. Okay, so once these pseudo code is verified, it can be converted into a program using the vocabulary and syntax programming language. Okay, so let's learn its advantages. Okay? So it is easier and faster to write as it uses English like statements. It does not need to be rewritten if any changes are made because it's step is independent and maybe more defined without altering the other steps, can be converted to a program using a programming language. Okay, so let me explain you with an example of this is a 0 basically in which we are comparing two numbers to know whether they are equal or not. So basically we have written a pseudocode in which we are comparing two numbers. So as you can see, number one, we have five and in them to v hat by these numbers are equal. Okay? So it'd be executed the first block, which is called as begin block, okay? And it will print the numbers are equally. In second pseudocode. It has y and in numb to it has six between you go into the else block. Okay? Because the numbers are not equal and it will print the numbers are. Okay. I hope you got it. Whatever I have explained you till now. And if you didn't understand anything, right, don't worry. In this course, I will be explaining you with the examples, with all examples of based on the real-life. Okay, So start learning now. Take care. Thank you. 2. Input Process and Output: Hello friends, welcome to our first chapter, which is input, process and output. Let's see what is input process and output in computers. Computer is used for storing and processing information. Computers follows principle of input, process and output for any problem. To perform this input process and output activities, computers need a set of instructions called a program. Let's see an example of input, process and output. You might have noticed computers being used at airline reservation counters, shops, restaurants, and various other locations. At each of these locations, user enter some values in the computer, and the computer generates an output which is other displayed on the computer screen or printed on paper. Let us consider the example of airline reservation counter. When you want to reserve a seat on a particular flight, you provide information about your requirements, such as destination, date, time, offer departure. The class in which booking is required. The reservation counter enters this information in a computer. The details regarding the availability of tickets are then displayed on the screen. The preceding automated process not carried out as one activity. It is broken down into a set of activities that are carried out in separate phases. Let us see what are the phases involved and the processes followed for each of the tasks. To understand what happens when you enter some values in the computer. Let us break the entire set of activities into separate phases. In the first phase, flight requirements are keyed into the computer. This phase is called the input phase. The flight information is then processed. Determine whether seats are available on the particular flight. This phase is known as the process phase. Once the processing is complete, the result is displayed on the computer screen indicating the status of seat availability. This phase is called output phase. The output phase. The cycle of activities performed by a computer is known as z, is input, process. And output cycle. Inflammation escaped into the computer. It will then process and the result will be shown or display on the screen. Now, computer consists of several components such as keyboard, a mouse, a monitor, or a printer, and a central processing unit or CPU. Each competent participants in either one of the input processes or output faces. For example, the keyboard and mouse are used for input. The CPU and the memory inside the CPU are used for processing. The monitoring printer are used for output. This is a figure of input processing output cycle. Now in next chapter, I will explain you algorithm, which is based on input process and output. Didn't understand this input processing output. Don't hesitate to ask me questions. Thank you. 3. What is Algorithm: Let's see what are the tools used in problem-solving. Before we actually start writing a program, we need to drive a procedure to solve the problem. There are various tools available to drive a solution to a given problem, such as algorithm, flowcharts and pseudocode. Let's first see what is an algorithm? An algorithm is a sequence of steps required to solve a problem. It is a list of well-defined instructions to solve a problem. Now suppose, for example, that we have to call someone. To call someone, we have to do the following work. First, we will check where the phone is turned on. Or node means dial tone is coming or not. The dial tone is coming. Then you have to dial the phone number of the person with whom you want to talk. After dialing the phone number of the individual, you will have to wait on the phone ring. Once it started drinking. The person you are calling a tensor call, then you can start talking. From this group of steps. We can understand that if we want to call someone, we have to follow certain number of steps. Now we can change these steps. Now what we can leave any step. If we ignore any of these steps, then we can not talk to the target person. The problem may not get dissolution. So for example, if we did it step two from the falling algorithm, then this will be called as incomplete algorithm because dialing a number is an E is N. Very important. Step to call someone. Let's see. Rules of algorithm. Algorithm will have five characteristics. First is an algorithm ends after a fixed number of steps. It stepped in. An algorithm clearly specifies the action to be performed. The steps in an algorithm specified basic operations. These operations could include calculations, input, output operations, and comparisons. An algorithm excepts input data in a defined format. Before it can be processed. An algorithm generates one or more outputs. After the input is processed, the resulting information termed as output can be displayed or stored. For future difference. Now consider another example that you want to withdraw a required amount from an ATM. The algorithm for this problem is, start the algorithm. Go to any local ATM, insert swipe, swipe your ATM card. But as the language button that you want to choose, enter the PIN code number. Press the account type savings occur in button from which you want to withdraw the money. The cash withdrawal burden. Enter the amount you want to redraw. Collect the amount from the ATM machine. Click this statement. You can make your ATM card. Now computer follows input. An algorithm follows. In computer, an algorithm follows input process and output cycle to solve a problem. Here, the input to withdraw a required amount from an ATM will be the ATM card, the pin code number, and the amount that you want to redraw. These inputs are then accepted in the process of withdrawing the amount takes place. At the end of the process, the amount, which is the output, is withdrawn. Consider another algorithm that displays the product of two numbers. First step will be to start the algorithm. Second step will be to get the first number. First step will be to get the second number. Fourth step will be to multiply that two numbers in the fifth will be to display the result is six. And the algorithm, as you can see, first number is four, seconds is nine. And when we went to this port number, we got the result 36. For example, if we delete step four from this algorithm, this algorithm will become incomplete. Algorithm must be in sequential, and it must complete every step. To solve a problem. I'm giving you two more questions to solve. And if you found any difficulties in solving these questions, then please ask me. I will definitely help you. In next chapter, we will see what is flowchart, which is based on algorithm and input process and output cycle. 4. What is Flowchart: Let's see what this flowchart flow chart is, a graphical representation of these steps to be followed for solving a problem. It consists of a set of symbols. Symbol represents a specific activity. Let's see what are the symbols in flowchart. This symbol is called input symbol. For example, you want to accept a number from the user. You will accept the number, or you want to prompt the user to enter a number in the system. You will do with input symbol. This symbol is called processing symbol. For example, you want to do calculations such as addition, subtraction, division, multiplication. So this will be done in processing symbol. This symbol is Carlos, output symbol. For example, you want to show or display the result of addition of two numbers, then you have to use output symbol. There is this symbol is called decisions in Berlin. For example, you want to know whether the condition is true or false, then you can check it in condition symbol. This symbol is called a procedure or subroutine symbol. This is called as flow lines. It is used to connect the steps of the flowchart and indicate the sequence in which the steps are to be performed. For example, if you want to connect input to processing and processing to output, we will use flow lines. Now this symbol is known as initiative or terminator. It indicates the beginning or end of the flowchart. This symbol is very important in flowchart because without this symbol, you can not start or stop flowchart. This symbol is known as on-page connector. It is used to connect one step in the flowchart to another step on the same page. This is known as off-page connector. It is used to connect one step in the flowchart to another step on a different page. Please don't get confused between on-page and off-page connector. On-page connector is used to connect one step on the same page. And off-page connector is used to connect one-step or another step on different page. This symbol is known as annotation. This is used to input comments on our flowchart. Comments can be inserted in flowcharts to provide explanation of the steps. There are some rules in flowchart. Let's see what it is that the logic of a flowchart should be represented using standard symbols. The flowchart should be clear, precise, and easy to follow. The flow chart should have only one start point, end point. The start and stop symbols should have only one single flow line. It is useful to test the logic of the flow chart by testing the flowchart using some temple values. Next session, I will teach you how to draw flowchart. And what is conditional execution. How to implement rehabilitative processing flowchart. If you didn't understand anything in this lecture, please don't hesitate to ask me. Thank you. 5. Flowchart Continued: Now that you know about the various symbols used in a flowchart, let us consider some examples where we use flowcharts to solve problems. Now consider the example of withdrawing and amount from an ATM. But before we start drawing flowchart, we must write its algorithm. Because algorithm will simplify your flowchart and it will show you step-by-step process to solve your problem. Let's see It's algorithm. You will go to an ATM to withdraw amount. You will first insert a swipe your ATM card. But remember, the most important step of algorithm is to write start the algorithm statement while starting the algorithm and the algorithm after finishing your algorithm. Let's come back to our loop algorithm. We will first start the algorithm. Then we will go to, you will go to any local ATM, will insert, swipe your ATM card. Then you will press the language button that you want to choose. Then enter the PIN code number. Then press the account type, whether it is saving or current button form which you want to withdraw the money. Then press the cash withdrawal button, enter the amount you want to withdraw. Colleague the amount from the ATM machine, collect the statement from the ATM machine, click your ATM card. And then the algorithm. Now let's see it's flowchart. As you can see, start symbol, which is the most important symbol in flowchart. But let me tell you one thing that before we start with flowchart, I will recommend you to learn by hardly symbols of flowchart, which I've taught you in our last lecture. Let's continue with flowchart. We will use start symbol first. Then we will use processing symbol to go to any local idiom. Then you insert an ATM card, which will come in input symbol. Because you are entering value in system. Or you can say you are giving information to the system. Then press the language button, which will also come in input symbol, because we are entering information in the system. Then enter the PIN code offer ATM card. It will also come in input symbol because we are entering some information in the system. So formula, you're going to understand that if you enter information in the computer, it will come in. Input symbol. This is off-page connector. We use this because we are connecting another flowchart. On. Next slide. Select your account type savings or current. And then press the withdrawal button. Anterior amount, colleague amount. Your clicker amount statement is in output statement. So the output symbol, because we are not entering any value in a DC machine, now we are giving command. We are collecting amount from ATM. So it will come in output symbol. Then colleague your ATM card, and it will also come in output symbol. Now we have completed our tags. So we will stop with the flowchart width stop symbol. Consider one more example where a number is accepted by us and incremented by one. And the result will be display. Means we have to accept the number, suppose five, and we have to add one to it. Then we have to display the result. Let's say it's flowchart. First we will start the flow chart with start symbol. The next epoch number, which will be in input symbol. Then add one to it, which will be in processing symbol. Now tell me why this statement is in processing symbol. If you know the answer, it's good, it's not. Then let me explain you. This is in processing symbol because we are doing addition at here. It means whenever you do additions, multiplications are any calculations. Then that calculation will come in processing symbol and do display the result. We will use output symbols. As you can see, at the result of adhesion is in output symbol. After completion, completing our tags, we will stop the flow chart. If you didn't understand anything, then please don't hesitate to ask me questions. Thank you. 6. Tools used in Problem Solving: Let's see what are the tools used in problem-solving. Before we actually start writing a program, we need to drive a procedure to solve the problem. There are various tools available to drive a solution to a given problem, such as algorithm, flowcharts and pseudocode. Let's first see what is an algorithm? An algorithm is a sequence of steps required to solve a problem. It is a list of well-defined instructions to solve a problem. Now suppose, for example, that we have to call someone. To call someone, we have to do the following work. First, we will check where the phone is turned on. Or node means dial tone is coming or not. The dial tone is coming. Then you have to dial the phone number of the person with whom you want to talk. After dialing the phone number of the individual, you will have to wait on the phone ring. Once it started drinking. The person you are calling a tensor call, then you can start talking. From this group of steps. We can understand that if we want to call someone, we have to follow certain number of steps. Now we can change these steps. Now what we can leave any step. If we ignore any of these steps, then we can not talk to the target person. The problem may not get dissolution. So for example, if we did it step two from the falling algorithm, then this will be called as incomplete algorithm because dialing a number is an E is N. Very important. Step to call someone. Let's see. Rules of algorithm. Algorithm will have five characteristics. First is an algorithm ends after a fixed number of steps. It stepped in. An algorithm clearly specifies the action to be performed. The steps in an algorithm specified basic operations. These operations could include calculations, input, output operations, and comparisons. An algorithm excepts input data in a defined format. Before it can be processed. An algorithm generates one or more outputs. After the input is processed, the resulting information termed as output can be displayed or stored. For future difference. Now consider another example that you want to withdraw a required amount from an ATM. The algorithm for this problem is, start the algorithm. Go to any local ATM, insert swipe, swipe your ATM card. But as the language button that you want to choose, enter the PIN code number. Press the account type savings occur in button from which you want to withdraw the money. The cash withdrawal burden. Enter the amount you want to redraw. Collect the amount from the ATM machine. Click this statement. You can make your ATM card. Now computer follows input. An algorithm follows. In computer, an algorithm follows input process and output cycle to solve a problem. Here, the input to withdraw a required amount from an ATM will be the ATM card, the pin code number, and the amount that you want to redraw. These inputs are then accepted in the process of withdrawing the amount takes place. At the end of the process, the amount, which is the output, is withdrawn. Consider another algorithm that displays the product of two numbers. First step will be to start the algorithm. Second step will be to get the first number. First step will be to get the second number. Fourth step will be to multiply that two numbers in the fifth will be to display the result is six. And the algorithm, as you can see, first number is four, seconds is nine. And when we went to this port number, we got the result 36. For example, if we delete step four from this algorithm, this algorithm will become incomplete. Algorithm must be in sequential, and it must complete every step. To solve a problem. I'm giving you two more questions to solve. And if you found any difficulties in solving these questions, then please ask me. I will definitely help you. In next chapter, we will see what is flowchart, which is based on algorithm and input process and output cycle. 7. Conditional Execution in Flowchart: Let's see what is conditional execution in flowchart. That are various situations where they need to perform an action based on a condition. This is known as conditional execution. Step by step process of solving a problem is not always sequential. At times it involves making decisions and repeatedly performing a set of steps. Let us see how conditional entropy due process can be depicted in a flowchart. First, we will see conditioning process than it. Next lecture we will see a repetitive process. Consider an example where we need to determine whether a number is even or odd. So we will start a flowchart, but start symbol. Then we will accept a number. For example ten, then DY DT by two. In processing symbol and check the condition in condition symbol. Now we have to check whether remainder is 0 or not. If the remainder is 0, then it will display the number is even and it will stop the flowchart. And if the remainder is not equal to 0, then it will display the number is odd and it will stop the flowchart. Let's consider another example in which we have to find the largest of the three numbers entered by a user. Let's see, it's flowchart. Start a flowchart with start symbol, also accepted three numbers in input symbol. Then we will check the condition in conditional symbol. We will check whether a is greater than or not. If not, then it will execute condition next to it. That is, whether B is greater than C to C or not. If yes, then it will display B. If not, then it will display c. Now, if a is greater than b becomes false, then it will execute condition which is below to eat. That is, it will check. Another condition, one more condition, that a is related to c or not. If that condition becomes true, it will display a. If not, then it will display C and it will stop the flowchart. You get me. We didn't get me. Please. Don't hesitate to ask me. Now I am giving you one more question to solve it your own. Let's see the caution that well, let's see the question. But the falling marks are given to students depending on the grades they have scored. Grid a will be excellent, Great, be very good. And great. C is good. You have to solve this problem. If we didn't, it will dissolve, then you can ask me. I will definitely help you. Thank you. 8. Repetitive Process in Flowchart: Let's see what is rehabilitative process in a flowchart. Programs involve certain processes that need to be repeated either for a definite or indefinite number of times. Consider an example where we need to draw a flowchart to calculate the sum of n numbers entered by the user. You will start the flowchart. And you will take two variables, that is y and sum. Then add. Why? With one that is 0 plus one will, one will get stored in y. And not the value of y becomes one. So the value of 0, sum is 0. So we'll add 0 with one. And again, we will get the result that is one and we get stolen some. Then we'll check a condition whether Y is equal to N or not. This condition becomes false because now the value of y is one. So the loop will continue until the value of y becomes ten. Then once it becomes ten, it will display the sum of n numbers. The loop will get stopped. At. The next slide. I will explain you about pseudo-code. Thank you. 9. Pseudocode: Let's see what is the pseudocode. Pseudocode is used to represent the logic of the solution to a problem. Once the pseudocode is verified, it can be converted into a program using the vocabulary and syntax of a programming language. Let's certain keywords in pseudocode. Let's see. It. One-by-one. Double black slash represents a comment, entry. Begin or end represents a block, which is used to start and pseudocode, except it is used to accept input. Compute it is, is to calculate the result of an expression. Display. It is used to display the output. If else, used to make decisions. For index, used to isolate a set of statements called substituting, used to invoke some pollutants. Let's see It's explanation one by one. Bean or, and these keywords are used to start and finish pseudocode is that told you? Begin is a first-line. And the last line of pseudocode. Except this keyword is used to obtain an input from a user. Display. This keyword is used to represent a result or an output. If else does, keywords are used in decision-making. Double backslash is for comment, do while. For repeat, FOR loop, do-while. Loop. To loop represents this all represents the loop. This is an syntax of pseudocode. So this is pseudocode to x. To add two numbers. Adding two numbers, we will accept the two number with except keyword. You will, then you will add these two numbers with compute keyword and some S variable. And the display, the output. We will use display keyword. So it will display the result. For Andy pseudocode. You will use and keyword. Next slide. I will explain you about variables and constants is new code, datatypes in pseudocode and some more examples of pseudocode. 10. Conditional Constructs in Pseudocode: Let's see what is conditioned. Consult. In pseudocode. Many problems require decisions to be made. All decisions may or may not state and action to be taken if the condition is false. The following types of decision-making constructs can be used in and see the code. If constructs and switches, switch case constructs. Post. Let's see. If construct. Simple. If construct, if the conditions specified is true. The statements contained within the if block are executed. Pseudocode segment to represent this simple if constructs are as follows. If you will, then we will check the condition, this bracket. Then the condition becomes true. It will execute begin Brock and provides the loop. The construct will exit from the program. Switch gets construct enables you to make a decision by selecting from number of choices. The pseudocode of this switch gears construct is as follows. Switch expression begin k is constant one. Execute these statements. Break. Gas constant is two. Now let me explain this with an example. The M is writing the algorithm for automated telephone call transfer. To wait Is departments of the company, such as marketing, finance, customer care, resources, and information. You have to write the pseudocode for the following problem. Start first. We'll make a flowchart. For particular pseudocode. We will start a flowchart. We start symbol. We will accept in a variable called data type numeric. So we will ask the user to enter the number from one to four. Then the number will get stored in n. And then we will check condition whether that n is equal to one or not means the number entered by the user is one or not. If it is one, then called WeTransfer to marketing department, if no, then it will check another condition that is whether n is equal to two unknown number entered by the user is equal to a naught. If it is Dan, It's called WeTransfer to finance department. If not, then you reject third condition. Whether the number entered by the user is three or not. If it is three, then transferred call to customer CAD department. If it is not in reject the fourth condition. If that become true, then it will transfer call to HR department. If not, then the loop will stop. So let's say it's pseudocode. So independent in pseudocode, the value of the variable and call is matched with a constant value, is matched with the constant value specified with the first case statement. If the value of n called matches these statements, in that case block are executed and the call is transferred to the marketing department. Otherwise, the control passes to the next case statement. This process continues until the value of n call matches with one constant value, or it reaches the default case. The customer controlled reaches the default statement, the call is transferred to the information department. No idea. We have three types of constructs. That is simple if conserved. If else construct a nested if else construct. We already saw if simple, if construct. Now we will see if else construct in the if else construct the statements within the if block are executed for condition being true. And this statement is within the else block are executed for the condition being faults. You can see if condition we can, we will check the condition in this bracket. If the condition becomes true, it will execute first, begin block, the condition becomes false to execute. Second building block, which is in else. Let's see an example of declared variables with num1 and num2. And its type is numeric. Then accepted the two numbers. And then we will check the two numbers. If condition. If the numbers are equal, then it will display the numbers are equal. Otherwise it will grow in Else block, which will display the numbers are not equal. Now let's see what is necessarily pulse construct. Pseudocode needs to be evaluated based on the condition within another conditions. In that case, you can use an if else statement within another if else statement. Let me give you an example. This isn't syntax of nested if else construct. First we will check the condition. If the condition becomes true, it will print the desert. And if the second condition becomes true, then it will print in Else block. And in third, in second L is block. You can see the statements to be executed based on about two conditions. Whatever conditions the statement will be executed. Give you an example of accepting two numbers and print the larger of two numbers. For this, we will take two variables, that is num one, num two. And we will check whether the number is equal to num two or not. If it's equal to num two, then it will display the numbers are equal. It will check. And the condition whether num one is greater than two, num two. If it is greater than number one, if the money is greater than num two, then it will display number one else. It will display num two. As you can see. We have to, if else in one pseudocode program. So this is called necessarily feels construct. So if you didn't understand anything, please don't hesitate to ask me. Thank you. 11. Data Types in Pseudocode: Let's see what is the return types in pseudocode and how to assign values to variables. So there are two types of data types in pseudocode. First is pneumatic and second is character and numeric. We can store only numbers. And these variables can be used in arithmetic operations. The variables which is declared as numeric datatype will be used, can be used in arithmetic operations such as additions, multiplications, divisions. And character variables can contain any combination of letters, numbers, and special characters, but can not be used for calculation. There are some rules to follow. Before you name a variable. First is the first letter of the variable may indicate data type used. For example, it can be either see or n to indicate a character or numeric variable as in C name and n h. The variable names should clearly describe the purpose. For example. And score is a numeric variable to store the score. The variable names should not contain an embedded space or symbols such as exclamation mark and symbol M. For symbol, you can use an underscore when space is required in a variable. Name, for example. And basic underscore salary. It will store salary in numbers. If a variable name consists of multiple words without spaces in-between, capitalize the first letter of each word for readability. Some examples are n total score and n sum of squares. Now you know the rules for naming variables. Let's see how to assign values to variables. Any variable needs to be assigned a value before its use. This is to ensure that the memory space located to the variable is initialized with a value. With a valid value. The variables can be assigned values in the following two methods. First is direct assignment. Second is Except Statement. In the direct assignment method. Values can be assigned to variables using the equal to sign as shown in the following syntax. Variable name. It's equal to value. Whatever value will be there, it will get stolen variable name. Let's see an example of direct assignment. Here. We are taking three variables, which is height, h and cold with datatype numeric and character respectively. Assigning value once and 172 to n height with the equal to sign. So at the time memory location of a computer will know that value 172 is getting assigned to height. And it will allocate a memory location and height variable with unique address of memory. Location means it will assign a unique address of memory location of n height variable. And this is applicable to n h and c code readable. Now let's see, Except Statement. Values can be assigned to variables except statement as shown in the formula syntax, except variable name. Indirect statement, assignment. We saw that we used equal to sign to store the value in the variable. But here in except statement, we are using except keyword. Except keyword will directly take input from the user and the value will be assigned to variable, whatever will be the name of the variable. Let's see one more example where we have to accept two numbers from user, and then we have to display their sum. First we will declare three variables. That is an num one, num two, and some with numeric datatype. Then we will prompt the user to enter the first number and it will get stored in num one. Then we will from user to enter the second number and it will get stolen. And num2 and the addition of both the numbers will get stolen and some variable D Got it. So if you didn't get anything, what I explained just now, then please don't hesitate to ask me. 12. Variables and Constant in Pseudocode: Let's see what is an variables and constants in pseudocode. A variable refers to the memory location whose value changes during the program execution. Constant refers to the memory location whose value does not change during the program execution. Now let's see how it works. When a user enters a value that is stored in a specific location within the memory of the computer. This memory location is given a user-friendly name, which is known as variable or constant. For example, we have a value which is ten, and it will get stored in num one. But what a processor will do, but what your processor will do is it will create different memory location for value ten, which will store only one value at a time. But it can vary throughout the program execution. You can see, however, a constant defers to the memory location that holds a value which remains fixed throughout the program execution. It refers to address of memory location. Let me explain you in detail. Consider an example of a program that accepts two numbers and displays the sum. This program, there's three variables stored in the embers entered by the user and when to store the sum of the two numbers. Each of the variables will map to a specific memory address. But the given scenario, the following variables are declared. Num one, num two, and some. You can say n sum. With numeric datatype. The variable and num. One stores the first number entered by the user, which is ten, and maps to the memory address 4560. The variable num to store the second number entered by the user, which is 15. And map to the memory address 456 to the variable. And some stores the sum of the two numbers, which is 15, sorry, 25, and maps to the memory address 4564. Address of memory location is constant and num one is variable, because address of memory location will not be changed unless until the name of the variable get changed. During computation, the program will refer to the variable num one to retrieve the first number ten entered by the user. And the variable. And num2 to retrieve the second number 15 entered by the user. The variable. And some will store the sum of the two numbers. Now there are two golden rules in variables. You need to declare a variable before using it in a program. The variable, sorry, the declaration of a variable assigns a name to the variable and specifies the type of data the variable can store. You need to declare a variable before using it. In a program. For example, numeric and num1 and num2 and N sum. This d variables are declared. Before we write our program. The declaration of a variable assigns a name to the variable, and it specifies the type of data the variable can store. We are assigning a name to the variable, and then we are assigning data type to a variable. So we have to do this, right, available. Or you can say to declare a variable. So if you didn't understand anything, please don't hesitate to ask me. Thank you. 13. Operators: Let's see what is operators. Programs are required to perform a lot more than just simple input, output, input, and output operations. All computer languages provide tools for some predefined operations. These tools are known as operators. The operators are categorized in the following ways. First is add the cooperator. Second is a relational operator. This logical operator. Let's see each operator one by one. The arithmetic operators are used for computation purpose. Example plus minus multiplication, division. Modular arithmetic operators. The more dilute divides two numbers and returns the remainder modulo symbol divides two numbers and returns the remainder. Relational operators. Second Disney second operator. Relational operators are used to compare two variables or constants. There are six relational operators. Firstly is less than, second is, firstly is greater than, second is less than. Third is less than, greater than equal to. Four, is less than equal to, is equal equal to 66 is not equal. You can see now when we are checking the condition within num one is equal to num two. Num one is greater than num two. Num one is less than num two. Num one is not equal to num two num one is less than equal to num 2. Third, operators, logical operators. Logical operators are used to combine expression containing relational operators. The following table describes the evolution of the various lobes logical operators. Assuming that the value of a variable number1 is to that of variable num two is six. Let's see. Each operator is an operator, N operator, all the conditions are met. It will be true. For example, we have a zoom. The value of num one is two. The value of num two is six. So let's check the condition. In example. With an example. Then num one is equal to equal to two and num two is less than. Num two is greater than four. Is this condition is true? Yes. The condition becomes true. So the result will be true. If any of this condition becomes false, then N operator will terminate. Means it will not execute. For an operator. Both the condition should be true. Second is OR operator. In our operator, if anyone condition met, it will print true. For example, of first condition is true. That is num one is equal to equal to two. But second condition number two is less than five is false because six is greater than six. And idea, it tells that six is num two is less than five. So this condition becomes false. But it will print true. Because this index of our operator is that only one condition should be true. Only one condition should be met through. Third is NOT operator. Not operator. Both the conditions should be false. As you can see, num two is less than equal to five, which is false because we have assumed that the value of num two is six. So six is not less than five at your condition becomes false, so it will print two. Let me explain you operators. With an example where a user is given a discount on a purchase based on the following conditions. If the D is not a Sunday, if the purchase amount is greater than $5 thousand. The falling for flowchart depicts the solution to dy. Preceding problem. You have to draw a flowchart where a user is given a discount on purchase if the day on which he or she is purchasing. Purchasing should not be sin D and E are cheap. Purchase. More than $5 thousand than their discount will be calculated. It's flowchart. Start a flowchart with start symbol. Except two variables with numeric data type, that is n, the amount of check the condition in decision-making symbol is not ND is equal to Q2. Sunday. Will check whether d is Sunday or not. If it is Sunday, then it will terminate and it will stop the flowchart. And if the D is not Sunday, then it will check next condition which is in an operator, but the amount is greater than 5 thousand or not. If this condition becomes true, then it will execute next step that is, calculate discount and it will flow chart. Suppose if this condition becomes false, means the amount year she purchased is less than $5 thousand, the flowchart will terminate. So if you didn't understand anything, please don't hesitate to ask me. Thank you. 14. Iterations: Let's see what is an iteration in pseudocode. Sometime programs become lengthy, not only because of complex decision-making constructs, but also because they are designed to perform tasks that are the protective in nature. It is the length of code in such a situation or iterative constructs can be used. One of the most important characteristics of a computer is its ability to execute a series of instructions repeatedly. This ability of the computer gives you a flexibility to control the number of times attacks to be repeated. Three types of identity constructs. That is, first is while loop. Second is the repeat until loop. And 30s. Let's see. First for loop. The for loop construct provides a compact, compact way of specifying these statements that control the repetition of these steps within the loop. For loop is classified as I iteration statement. The for loop consists of the following three parts. First is initialization expression, second is evaluation expression. Third is increment decrement exploration. In this initial addition expedition, the numeric variable is initialized using a variable value. Initialize the next fission. And numeric variable is initialized using a value. In evaluation expression. The condition is tested at the beginning of iteration of the loop. When the expression evaluates false, the loop dominates. This is an very important expression in follow. This an increment, decrement expression. In this, the value of the variable is increased or decreased intake. So for-loop me show you in a flowchart of for loop. And it's flew off. That is flow of for loop. First, it will initialize a valued condition. Then if the condition is true, then it will enter in the body of the loop. If condition becomes false, then it will exit from the loop. After executing the body of the loop, it will execute increment. It will do increment or decrement of variable by one. Whatever the value is specified in the loop. Then it will again go to valued condition. I know it will continue looping until the condition becomes false. Once the condition becomes false, then it will exit from the loop. Just remember to initialize only for one time. And the process will do all things. Considered an example, that XOR five numbers and checks whether the number is even or odd. If the number is even, display the message the number is even. Otherwise, display the message the number is odd. We have to accept five numbers and check all the numbers, whether it is even or odd in for loop. So first, we will begin our pseudocode bit begin keyword. Then we will declare two variables with numeric datatype. And then we will use for loop. We will take first number 0. It will be five numbers from 0 to four. Our first condition in for loop is n z t is equal to 0, which is initialize this next question and 0 will get stored in and CTR. Our second condition is test expression. It will check whether NCT r is less than equal to s4 is less than, less than equal to four. This condition is true because in NCT our variable, we have 00 is less than four. So this condition is true. It will enter into the body of the loop to begin keyword. And it will oxidate to enter ox user to enter a number. Suppose user has entered ten. Then it will store that number in one variable through except keyword. Then it will check if condition. Then it will check. If condition whether the remainder of division is equal to 0 on this sign is called modulus sign. It divides two numbers and returns the remainder. So the condition will become true and it will display the number is even. Add here, our first iteration ends. After first iteration. We will go on and CTR is equal to NCT r plus one. It will add one to NCD, as you can see here. Now, it will again check the test expression. Whether NCD r is less than or equal to four or not. If it is equal to four, then the loop will terminate. If it is less than four, then it will enter into the body of the loop. But after doing calculation, the value of n cdr will be one. As you can see here, the value of NCD r is one. Then it will go, the condition becomes true. Then it will go in the body of the loop. And then it will display the number. Suppose we have entered 12. Now that 12 will be accepted in num one. And then we'll divide 12 v2, we will get remainder 0. This condition also becomes true because we have to find the remainder of 12. Idea. We are checking the remainder of 12th in if condition. And this condition becomes true and it will display the number is even. Then again, it will go to NCD, our NCT. It will add to another one, sorry, it will add one. Now the value of entity or is one, then it will add one to it. Then the value of entity or becomes two. Then it will check condition whether it is less than four unknown. Yes, two is less than four. It will display number. Now suppose now we will enter seven. So seven will be accepted in num one. And when we divide seven by two, we will not get remainder 0. That means this condition becomes false. It will go in as block and it will display the number is odd. Then after the loop ends, it will add one more to it means now the value of entity r is two. It will become three after adding one to it. As you can see you, they will check condition whether it is less than four or not, the condition becomes true and it will display number. Number will be accepted in num one means that is stored in num one. Now we are taking six even number. Then we will divide it by two. We will get remainder 0. It will display the number is even. Then it will go to another loop. Then it will again go to MTTR and it will add one to it. Now the value of entity or becomes one, it will become four. So it will check whether NCT r is less than or equal to four is not less than four, but it is equal to four. So again, accept a number which is nine. We will divide but two, the result will be false, so it will display the number is odd. Now idea of flowchart means our pseudocode is finished because we have achieved our tax. That is, we have to check whether we have to take five numbers and check whether it is, it can be divided by two or not. This remainder is true or not. Then after finishing our iteration for five times, it will exit from the loop. Because now the value of MTTR becomes five, which is not less than four. So it will end the loop. Let's see what is while loop. The while loop executes as long as the conditions specified with the while loop is true. The moment the condition becomes false, the loop breaks. The while loop construct can be used for both fixed and variable loop. This is an iterative construct with our text expression at the top of the iterative statements. Iterative statements. This is syntax of the while loop. It is in pseudocode. So fast it will check condition, then it will exit the body of the loop. What happened in fall loop? It will check first. First it will initialize expression, then it will test the condition that it will. And then it will test the condition. If the condition becomes true and it will enter the body of the loop. But in while loop, the condition becomes true. It will enter the body of the loop. Let's see an example of a while loop where we have to write a pseudocode to display the average score of 30 students in a school. So for this, we will declare four variables. With number, with sorry, with numeric datatype, we will initialize N, max and total encounter an average that is ABG with 0 and one respectively. Then we will check the condition whether in but then counter is less than two or not. Condition becomes true. Then after we have initialized encounter with 0, sorry with one, this condition will become true. I need to enter in the body of the loop. Then it will ask the user to enter the total marks of the students. The max of students will get stolen and Max through except keyword, then the total will be calculated and it will get stolen and totally variable. Our first loop ends. It isn't continuous process. So we will add an encounter with one. Now, the value of encounter is one. Sorry. We will add an encounter with one down. The value of encounter becomes too, because first we have initialized it to one. So one plus one, it becomes too. Now the second loop has been started. It will again check condition and it will run 30 times like this. It will run 30 times, it will check. Again. It will check in while condition, will ask the user to enter. Like this. It will check what for d times one, the condition becomes false, means the value of encounter becomes 31. It will calculate average. It will divide encounter with value to a t with whatever will be the total. After getting the result, it will display the average marks of the class. Whatever will be the average level is lowered over will be the average. It's flowchart. As you can see. We have started flowchart with start symbol than you have taken. Four variables. Counter total average marks. Then initialize counter with one total average and max initialized with zeros. And we check condition in while loop. Whether is encountered is less than the curator ds will display the number, then N total is equal to add marks to the total. Add one. To encounter. It will become two. We check for 30 times. The loop will continue for 30 times after the. So, after being the encounter, the value of encounter being 31, the loop will check condition and it will become false. So it will calculate the average. And it will display the average of 30 miles. 30 seconds. Let's see what is repeat until loop. The repeat until loop differs from the wild loop only in the way the condition is evaluated. In the while loop. The condition is evaluated for tested before the body of the loop begins. Only if the condition is true, the control moves to the body of the loop. In the repeat until loop. The body of the loop is executed once, regardless of the condition being true or false. And then the condition is evaluated. The loop is executed. If the condition is false, the moment condition becomes true. Loop breaks. Syntax of repeat until loop. Repeat keyword will be used idea. Then it will check condition in until keyword at the end of the loop. Consider an example that calculates the sum of two numbers entered by the user. So we will start with the go-to music in keyword, sorry, begin keyword. Then we will declare four variables with numeric datatype. And we will assign value 0 to it to all four of them. We will use repeat keyword to start our repeat until loop. Then we will ask the user to enter the first number. Then the number will get stored in num one. Then we will ask for second number, then that will be get stored in num two. And the result will get stored in. And some display keyword will display the endosome. And then we will add one to and counter. And it will repeat the loop till, until, until n counter becomes ten ones. Then counter variable becomes greater than ten. That is 11. Then the loop will break. The loop will break because we have calculated the sum of two numbers entered by enter ten times by the user. Now I'm giving you two cushions for practice. If you didn't understand anything in this session or if you are not able to solve any questions or if you have any doubt, then please don't hesitate to.