Transcripts
1. Course Introduction: So welcome to the course on Control Flow
essential wherein we've been mastering
conditions and control flow with the
help of JavaScript. My name is Fesil and
I'm excited to be your guide as we dive into the fundamental
concepts that make your code dynamic and
very much responsive. In programming,
controlling the flow of your application
is really essential, and this course is designed
to help you understand how to make decisions and repeat actions effectively
in JavaScript. Now, if you're new
to programming or looking to solidify
your understanding, you will gain a
comprehensive understanding of all the concepts that we
are going to talk about, and you will also
learn about writing clean and logical code that can help you build
some amazing projects. Now, here's a sneak peek of
what we are going to cover. So we're going to
cover if statements wherein we'll be talking
about how you can execute certain blocks of the code if certain
conditions are met. We'll talk about switch
wherein we'll discover a powerful alternative
for handling multiple conditions in a
neat and organized way. And this is really important. It's something that
we'll be doing hands on. And then we are going
to talk about loops wherein we are going
to cover four loops, wherein we'll talk
about the art of iterating through the data
with the help of them. We'll also talk about why loops wherein we understand
how you can repeat certain actions until
a certain condition is met. And by the end of this course, you will have a strong grasp
of JavaScript control flow, enabling you to build
more interactive and action oriented
intelligent applications. So who is this course for? This course is for
developers of all levels. So whether you are a beginner, intermediate level developer or someone who is very
advanced and who is looking to get a refresher
on all these topics, you can happily
join in the course and you will have a great time. Also, I don't make use of a lot of presentations.
Everything is hands on. I show you things, and then
actually see it in action. Okay? So that's how
we'll be going about. It's a completely hands on code, so don't worry on that part. So are you ready
to take control of your code and create dynamic
interactive programs? Let's dive in and start mastering conditions
and loops together?
2. Decisions in Action: Mastering If-Else Logic: Hey, what's up, everybody. So it's time that we talk about if statements
in JavaScript. So if statement is
used to execute a block of code if the
specified condition is true. So yes, the center of if statement is the
condition that you specify. And depending on the condition, it's decided whether the block of code should be
executed or not. Now, why do we need something
called as if statement? Now, there will be
scenarios wherein you might want to do conditional
execution, right? Now, what is
conditional execution? Conditional execution,
meaning how programs are executed is
you have console dot log, you have line one,
okay? Line one of code. Okay. And then you have
line two of code, okay? So this is not conditional. It is being executed
one after the other. Now, let's say I
want to execute line one of code only in
a certain scenario. And that is where if stattment
comes into picture, okay? So I might want to execute or I might not want
to execute a line one, depending on whether a
certain condition is met. Right? Now, a
condition could be, let's say if the temperature
is greater than 25, right, or greater than a
certain amount, then I would want to
show a message to a user that it's
hot today, right? So you cannot just
print it's hot today. You have to first
check the temperature, and if temperature is
about a certain threshold, only then you have
to show the message. So this is where conditional statement comes into
picture, right? This is if is not the only conditional
statement that exists, right, but I'll show you
how you can make use of I. So you can say if over here,
you have the suggestion. If statement, you
have ILs as well, right, but we'll
stick to if for now. You have to specify condition
that evaluates to boolean. So let's say I'll
say true over here, o and I'll move line one
inside if statement. Now this curly breeze
represents a block of code, and within this curly breeze, you can add any number
of lines of code. That will be executed if
the condition is met. Now if I save this, you'll see line one line two, and if I convert this
to falls over here, you will only see line two. So this will never
be executed because the condition within
the if is false. All right? So that is how if treatment works
in a nutshell. Now let us come back to
our example where we say, if a temperature is about
above a certain threshold, we want to show a
message to the user. So for that, I'll
need a variable. Okay, so I'll say temperature. Okay. Now, let's say if the temperature is
30, record it today. All right. So I can
have E condition over here so I can see if
temperature is greater than. Okay? If it's greater
than, let's say, 25. Okay. So if it's greater
than 25, I wish to print, it's a hot T something
like this. All right. So this can go in and over here, this is outside if right? So you can see, or I can
just print, have a nice day. Okay. So you can
see it's a hot day and have a nice day is
being printed now. Okay? If the temperature
is 22 over here, then you'll just see have a nice day because it's
not a hot day, right? So I don't want to
print that. All right? Now, what this
means is this block of code is executed if this
condition is met, right? Now, there will be scenarios
wherein you want to execute some block of code
when this condition is not met or this
condition is false, and that is where statement
comes into picture. Okay? So you have I and
then you have s over here. Okay? So I can let us have
a variable over here. I'll say it is
raining over here. Or let's deal with the
same example over here. So I can say it's hot today, and I can say se
over here, okay? And you can add over here
Console dot Log over here, and I can simply copy
this it's not a hot day. Okay? You can see it's not
a hot day, have a nice day. And if this is 26 over here, for example, it'll
say it's a hot day, have a nice day. All right. So this is an example
of Is treatment. Let me give you
one more example. We'll pick an example
of a rainy day and we'll have a variable
is raining over here. Okay? Now, if it's
raining, if it's raining, what we need to do is
we need to say Console, dot log over here, and I need to say take an umbrella, right? Something like this.
Okay. And otherwise, I need to say okay, I need to say no need
for an umbrella, right? So yeah, I'll say. No need for an umbrella. I'll save this. So you can see take an umbrella because it's raining and
if it's not raining, you can see no need for
an umbrella. All right. So pretty
straightforward, right? Now, here, what we are doing is we are having two
blocks of code that is being executed if this
condition is true of all. So this condition is controlling
everything over here. So this condition is important. So if you're writing
if statement, be sure to have this
condition right. Okay. Many people make a mistake that the condition,
they don't get it right. Okay? There is some
logical error, and then they don't
get the right output. So just keep attention
to this condition. Now, there is one more
form of IL which is if, and then you have if
and then you again, have s. So this
is also possible. So you can say if over here, you'll see FL
statement. All right. Now I can say, I now using
this syntax over here, I s if s, you can actually chain
multiple conditions, right? So let me show you how, okay? So let's say I have a variable
over here called score. Okay? Let's say, I'll assign
this a value of 75. Okay? Now, I'll have score
over here, ok? So I'll say score I score is
greater than equal to 90. Okay. Let's say we want
to print something. What are we printing over here? Okay? We want to say excellent. Okay. Now, what actually we are building is we
are actually building a condition over
here that is going to print different messages depending on what
your score is. Okay? Now, let's say I want to have a message that prints good job
if your score is above 75, and if it's above 50, you want to say you passed. Otherwise, if it's
lesser than 50, better luck next time,
something like that. Okay? So I got this.
Okay, I got this right. I will print I'll print excellent if the score is
greater than 90, okay? Now over here, I want to
evaluate one more condition if the score is greater
than 75, right? So what I will do is
I'll get this and here, I'll add this condition.
Okay? So I can do this. This is completely valid. And here, instead of 90, I can have 75 over here. Okay. And instead of Oops. So let me copy this properly. Okay. So I can piece this
and I can say, good job. Something like
this. Okay. Now, I want to have a
condition which says, if the score is greater than 50, I need to say you passed. So I'll just paste it over here. And if the score
is greater than, let's say 50, I can
say you passed. Something like this.
Okay. And let's say if this score
is less than 50, okay, you need to say
better luck next time. So if this score is not matching
any of these condition, I need to say over here, and I can just say
console dot log. Oops, I just need
console dot log. Okay. So I'll get
console dot log, and I'll say better luck next time. Time, something like this. Okay? So you can see over here, I am actually chaining
multiple conditions. This is condition number one, the condition number two,
condition number three, and then you have the
else block. All right. Now if I save this, okay, you can see, good
job is printed. Okay, because the score is 75 and it is matching
this condition. Score is greater
than equal to 75. Okay? If it's 80, you'll see good
job being printed. If it's 95, you'll see
excellent being printed. If it's 51, you'll see
pass being printed. And if it's 44, let's say, you'll see better luck next
time being printed. Okay? So multiple conditions have multiple blocks of code, and multiple blocks
of code are being executed depending on
which condition is true. So this is known
as chaining, okay? Chaining if L if L. Okay, so you're actually
chaining the conditions over here to form
a sort of chain, and depending on the condition, the right one is executed. Okay? Now, beyond chaining, you also have something
called as nested IL, okay? So what you can do is, let's say I have an application, okay? And within the
application to enter, the user needs to
have age greater than 18 and also needs
to have permission. Okay? So let's say permission is just a
flag right now, okay? So I'll say has
permission over here. True for now. Okay?
It's just a flag and this flag is being derived from some conditions
in our application. Okay? And age, let's say, is 20, for example. So in our application to enter, we need to have age greater than 18 and
also the permission. So I'll say if over here, I'll say age greater
than equal to Oops. So it's greater than
equal to 18 over here. Okay. And then I can say, so this condition is evaluated. Now, if this is true, I need to add one more
F over here to check if he has permission because he also needs to have
permission to enter, right? And then if he has, I
can say console dot log, you are allowed to enter. You can say you are allowed to enter over here.
This is done. Okay. Now here, you can
even add se over here, and you can add a
console law over here. You need permission to enter. Permission to enter,
something like this. Okay? And you can add. So this is the I
block out of block. You can add block also, and you can paste it over here. You can say, you are not
old enough to enter, something like
this. You can see. So you can see over
here you are allowed to enter because both these
conditions are matching. If I change this to 17, you'll see you are not
old enough to enter. Even though he has a permission, he's not allowed
to enter because this condition
itself is failing. So this internal condition
is not executed. We just ask him that
we just tell him that you are not allowed to enter or you are not old enough
to enter. Okay? Now, let's say if he is
20 and if this is false, then in that case, you'll see you need permission to enter, because even though he's
matching the age bracket, he's not having the permission. So what you're doing is
you are nesting, okay? You are nesting if Ls and
nesting meaning you are having one ifs condition within
another over here, okay? Now, you can even
simplify this over here. You can simplify
this condition with the help of logical operators. Okay? So what you
can do is you can make use of and operators, not this one and operators
in if condition. Okay? So I can say
let is weekend. Let's say we have an app
that is keeping track of holiday and whether we can
relax today or work today. I can say is holiday. Okay. And over here, I can say force,
something like this. Okay. So I can say
if is weekend, okay? So if it's weekend
and if it is holiday, okay, then I need to show a message that you
can relax today. Okay? So you can relax today. Now what we are doing
is we are having a you're actually checking
two variables over here, and you are using or operator. Now, the output of this
is Boole in, right? So the output of the
condition over here should be boolean for F statement
to work fine, all right? And that is what we
are doing over here and we are having an s block, and we can say it's
working day today. Okay? It's working day. Something like this, right? So you can see you
can relax today, and you can see over here. So if I say this is false, and if this is false, you'll see it's working day. Okay? So yeah, this
is how it works. You can even make use of and
operate over here, okay? And you can actually see
the output over here, okay? This is an example. All right. Then there is something
called as ternary operator. So ternary operator
you will be aware of, which is sorry, question
mark and colon. So these two things get
you a ternary operator. Okay. So let's say if I
have a number over here, and if the number
is seven, okay, I can say let result over
here is equal to number, percentage, seven or sorry, not seven, two over here. And if this is equal to zero, then I'll say it's even. Otherwise, it's odd, okay? And I can just print
console dot log here. Okay. So here, I can say result. You can see it's sod, right? And if I make it eight, Oops. So if I make it eight,
it'll be even over here. Okay? Now, the same
condition you can even write with the
help of if statement, so you can say if all right. And what is the condition?
This is a condition, right? So you'll get the
condition over here. Okay. And then you need to like return this or assign this to result,
right? Over here. What I will do is I
won't assign this, but I'll actually take
console dot log directly, and I'll just have a result. Oops. So I'll say result over here and I'll
say even over here. Okay. Something like this. Okay. And if that's not the case, then what you can
do is you can print or. Something like this. You can see even, even. Okay. So it's the same condition actually written with the
help of if statement. But in cases, ternary operator gives you
a more concise syntax. Like, for example, over here, the condition is pretty simple. So ternary operator is
looking much more concise. But now, if the
condition is very complex like this one
or nested condition, then it's advisable you don't make use of
ternary operator because either you will end up making mistake or the person
who is reading the code, he won't understand
what's happening, right? Because it
won't be readable. It would be a mess. So
for simple conditions, ternary operator is
advisable, okay? But for complex ones, of course, you need to make use
of normal ifs, right? So that's something that
you should be aware of. Of course, you can even move
this to functions, okay? You can even make use
of IL in functions. So, uh so function. So you can say function,
check, even odd, something like this over here, and I can have this
condition over here, okay? And number is ended, right? So you'll get number over here. All right. And you
can call this. You can say check,
even odd, okay? And you can pass in ten, for example, ten is even. You can pass in 11. You can see 11 is odd. So this is also possible. Okay, you can have Fs in, uh, in functions as well. You can make use of ELs
with arrays also. Okay. Let me show that to
you. Okay? So let's say you have array
of fruits, okay? And you're having apple, okay? I'll just create a
few fruits, banana. Okay. And let's say
orange. Pretty simple. Okay. Now, let's say I want to check if
my favorite, okay? Fruit exist in the array or not. Okay. So let's say
my favorite fruit is apple, for example. Okay. So you can
say if all right. Okay, 1 second, let
me get this template. So you can say if what
is the condition? If fruit includes, you
have includes over here. Okay. If this includes
your favorite fruit, okay? Then what you can do is you
can log over here, okay? You can say I'll just say yes. Okay. Otherwise, what you can do is you can say console
dot log over here, and here you can say no. Okay I'm just printing
simple yes or no. You can have good
messages of course. So you can see yes over here. Now, let's say, if it's
strawberry my favorite fruit, then it's not there in the list. Okay? So this is how you can
make use of arrays with FLS. A right? You can have operations that
return boolean value, and that could be valuated
in FLS conditions. Okay? You can even
do this with Objecs. So let me show you an
example over here. Okay? So let's say I
have a user over here. User. All right. Oops,
I must equal to. Okay. Within user, let's say
you have a name of Alice. Okay. Let's say you
have is admin as false. Okay? So here, this is
a boolean value inside, like a boolean attribute. So you can say I okay
I'll get DL template. You can say user dot is Admin. Okay? If he's Admin, you can say console
dot log over here. Okay. And you can
say, welcome Admin. All right. This is possible. Okay. And otherwise,
what you can do is you can come over
here and you can say, Oh, you can make use of
template literals over here. Okay? You can say user
dot n. All right. And then this needs
to go in back taxes. Okay? If you save this,
you'll see welcome Alice. Okay? So is user
EdminFals, right? So you'll see welcome Alice. If this is true, Welcome
admin. All right? So I'll keep this as false
and we'll have welcome Alice. Okay? So summary IL statement is one of the important control
structures in Jascript. Okay? It comes under so
there are categories, okay? So you have control structure, meaning you are controlling how your clue your code
is executed, right? So if statement comes
under that, okay? And it is used for
conditional execution, you can see here we are
executing code conditionally. If you're making use
of If statement, there is no guarantee that
the code will be executed because it would depend
on the condition, right? And the value values
involved over here. If you have complex condition,
you won't know, right? So ILS is very fundamental. You will be using FL a lot, whether you learn Javascript, react, all of that, all right? And there are multiple
forms like we saw. You have basic if if with Ls, you have if chained together, you have nested IL, you can make use of
logical operators to create more
complex conditions. You have ternary
operator as well, which is a shorthand
version of FL statement. So ternary operator
is often called a shorthand version
of FL statement. Okay. And Is can also
be used with functions, arrays, objects, and
so on. All right. So I hope you are clear
as to how you can make use of decisions in your code with the help
of a first statement, and I hope this
was super useful.
3. Switching Perspectives: A Deep Dive into Switch Statements: So now it's time that we talk
about the switch statement. Now, let us first understand why switch statement exist
at the first place. Now the problem is
when you are dealing with multiple
conditions with ifs, there can be a problem that they become a bit more lengthy
and hard to read. And this is a case
if you are doing condition evaluation on the
same variable, all right? So when dealing with multiple conditions for the
same variable, if se can become lengthy
and harder to read. Where switch statement comes
into picture wherein it offers a cleaner and more
readable alternative. All right. So let me give you an example of what multiple conditions on
the same variable means. So take a look at this example
over here that I've added. Here, I have a
variable called fruit. I'm evaluating this variable, okay across multiple conditions and giving the output
over here, okay? Now if I save this, of course, I'm going to go I'm going
to get the output as apples are $2 per kg. Okay? So I'm getting
the price over here. But the conditions
are multiple, okay? For one or two condition, IL statement is great, but when conditions
grow like this, okay, it can become
difficult to manage. And this is where switch
statement comes into picture. So how do you write a switch? So you can say over here, let's say I have, okay, here I have fruit. Okay, I'll create
another example. I'll call this as fruit type. So the variable will
change over here. I'll have a switch on fruit. Okay. So actually, if you
type switch over here, you have this template
that you can select. Okay? You can see the syntax automatically added over here. Now, switch statements
consist of keys and values. Okay? So here you
can see this key. So what is a key over here? Key is actually the expression that I wish to evaluate, right? So here, in my case, the expression is fruit type. Okay? So this fruit type now will be evaluated
against multiple cases. So case one is over here, Apple. Okay. So I can say
apple over here. Okay. And if it's apple, then what I want to do I want to print in this
statement over here. Okay? Something like
this. All right. So I fruit type is apple, this will be executed this case because it's
a matching value, okay? And it will print
this to the console. Okay? I can replicate this
for other things also. Okay? So for example, I can
have it for banana, right. So here I can say
this is banana. All right. And I can have the console log over
here for banana. Okay. You can see. Okay. I can do similar thing
for other fruits also. So I'll add this. Okay.
Oops. Indentation, I messed up with the indentation. All right. But after
banana, there is orange. I'll say orange over here and what is the
console lock for orange? Oge oranges are 1.5 dollar
per kg like you can see. Okay? Now default
is the default key, when no match is found, so you can get this printed. Okay? Over here. Okay. Something like this. All right. Now,
if you save this, you can see apples
are $2 per KG. If I make this as
strawberry, okay? You'll see sorry we
don't have that fruit. If I say orange, oops, not over here. If I say Okay. So if I say
strawberry, actually, I change a wrong
place, you should not change at the case place. I'm sorry about that, but
it will be strawberry. Okay? If you save this, you'll see, sorry we
don't have that fruit. If you say orange, Okay, oranges are 1.5 dollar per Kg. Okay? If you say banana, the banana one will be
executed. You can see. So this is a better alternative, I would say, easier
to read, okay? And it's easier to
manage as well. So if you have more cases
or more fruits being added, you can simply add a case
statement. It's easier to read. But over here, if you
have multiple conditions, okay, it might be
cumbersome to read. So that's the benefit over here. Okay. Now, you can have fall
through in switch as well. Okay? So let me copy
this entire thing. I'll come over here. Okay.
I'll show you fall through. Okay? So I'll say fall. Two. And I'll get rid of this.
This is duplicate actually. So let's say I have
this switch statement. Now I want to group multiple cases to execute
the same block of code. So what I can do is if
the fruit type is apple, then I want to execute
these two cases. So what I would do is I would
remove break over here. Okay? Now, if I say, Okay, so let me change this too. I'll move this to a normal
variable, and over here, I'll say fruit type is
equal to apple. Okay. Now, if I save this,
you will see apples are $2 per kg and
bananas are $1 per kg. You're getting both of
these printed over here. If you say banana, only
one will be printed. Okay? So why both were
printed when you said Apple? Well, what is happening is here you don't have this
break statement. So break in a switch
case is responsible for breaking the loop over here or breaking
the condition. So here, once this is
executed, this part, break statement is uncounted and the control does not
go to the next case. Instead, it comes
out of the switch. So break is essentially used
to exit from switch, right? So if you skip break, it will go and start executing
the next case also. If I remove this, it will go again and start executing
the next case, you can see. Okay, so that's the
importance of break. And this behavior over
here without break is known as fall through in switch. Okay? So just remember this if someone asks you or if you
read this anywhere, ok? This is known as fall
through, omitting of break. All right? Now,
you can even have a switch with expressions. Okay? So let me say switch
with expressions. Okay? All right. I made I'm spelling
mistake over here. Okay? So let's say I
have a number over here, which is initialized to
let's say nine, all right. Now you can say
switch over here. Okay. Now I can say true, because this expression
is not true. Okay. So now what you can
do here is case. You can have number
is less than five. So if number is less
than five, okay, you will say console
dot log over here. Okay. Here, you can say number is less than five,
something like this. Okay? You can have
similar thing for oops. You can have similar thing
for this part over here. Okay. So you can say here, number is greater
than equal to five and number is less than five. Oh, sorry, number is not less than five,
it's less than ten. So here you can see
number is 5-10. So you can see number
is 5-10. All right. So this way, you can
make use of expressions in case statements as
well, right over here. Now, I want to talk
about differences between switch in JavaScript, Pis in and Java. All right. So in Java, so this
examples that you're seeing is similar
to the ones that we have exam in Java, okay? So in Java, also, it works
the similar way, okay? And in Java, case values
must be constant. Like in Digo enums or strings. But in case of JavaScript, it can be of any data
type like strings, numbers, and it can even include expressions like we
are seeing over here, right? And with respect
to Python, okay? So Python does not have a
traditional switch statement, but it uses if Ls, if, all right. So
that's something. In the latest version of Python, you also have match key, which is a more
powerful construct than JavaScripts switch, right? So yeah, this is what it is, and the syntax will be much more similar to the other
programming languages. But one thing you should remember about switch is
when should you use it. So if you have
multiple values to compare against a single variable like we are
doing over here, it's better to use
switch because they are much easier to
understand and write also. Like, you'll be making less mistakes and someone reading it, it will be much more
easier for them also. I hope this has been useful and you have been
able to follow along.
4. Iterate to Innovate: Harnessing For Loops in JavaScript: So now it's time that
we begin talking about the four loop in JavaScript. Now, JavaScript four loops work like any other programming
language, right? So let's say I can write a
four statement like this. You can see this syntax that
got populated, all right. Now you have this index, which will be like
a counter that will help you go through a
list of elements, right? So I can have I
over here as index. Okay. I can start from zero. Okay, so I is equal
to zero, and Oops. So I can come over here, right, and I can have less
than five over here. Okay. Let's say, let's say ten. I want to print numbers 0-9. Let's say, I want to
print ten numbers, right? I have I plus plus, and I can simply come
over here and say Console dot log over here. Okay. And I can have I printed. Like so. All right. And if I save this,
you will see zero, one, two, three until nine. So ten numbers are
being printed and we are actually making use of
four loop for the same. Now, if you have an
array, basically, so four loops can be beneficial in iterating through the arrays as well over here. So if I say numbers over
here and you can have one, two, three, four, five,
six, seven, eight. Okay. Let's say we
have eight numbers. So I'll copy this, Alright. And over here, I can
say numbers dot length. This is a array, and we have this length
property along with this, okay? And you can access
the array over here. So you can say numbers in I. If you save this, you'll
see one, two, three, four, five, six, seven,
and eight over here. Okay? So we have this
array being printed. Now what is happening is this
is the initialization part. We are initializing
the variable. This is the conditional
part where we are evaluating the condition whether the four loop should
move forward or not. And this is the increment part. So first, the
initialization takes place. Then condition is evaluated. So is zero less than
numbers dot length. Okay. So zero is less
than eight over here. The length of this
array is eight, right? So numbers dot length will be eight because we
are trying to get the length of the arrays using the length
property, right? So since it's true,
we'll come inside and you'll print numbers
of zero, right? So which means one gets printed. Then you increment I and then you evaluate
the condition again. And then you go inside. If the condition is true, you go inside and execute this. This way, this
four loop keeps on executing until the condition over here turns out to be false, right, and the loop is exited. Okay? So this is how
the four loop works, and this is the counterpart. This is the initialization part, and this is the increment
and decrement part. So initialization is just executed in the beginning
of the four loop. Right? Later on just
these two things are taking care whether the loop should be executed
or not. All right? So this is about a four loop, and you can even make
use of four loop for printing reverse over here. So I can go reverse.
Let me copy this. So this was a forward
printing loop. I can actually make
this as ten over here. I can reverse the condition that it should be greater than zero, and I can have I minus minus. If I save this, okay, and let me comment this so
that there is a little bit of less log onto the screen, you can see over here,
109-87-6543 21, right? So we are going reverse
now with the help of this four loop so it's helping us go in
the reverse order, and you can do the same with
the array as well, right? You can print reverse, print array in reverse. That is something that
you can do. You can even nest the four loops, okay. So I'll just comment
this over here so that we have a cleaner console and we can see the
output over here. So let's say I have
this array, o, and let's say I wish to print
a matrix, sort of, right? So what I would do is I
would come over here. I would also add a
four loop over here, ok. And I'll just comment this. Okay. What I would do is
I would start from zero. I would say I is less than. I can say, oops, sorry, I is less than, let's say ten, I plus
plus, something like this. Okay. Now, I'll say I is equal
to zero over here as well, and this inner loop will match. So first of all, we need to change the
variable name over here. This should be J.
Okay. This also should be J and this
also should be J. Okay? So J until J is less than I G plus plus,
something like this. Okay. And you can print
in J over here. Like so. If you save this, you'll see. Okay, so zero, one, zero, okay? One, 20. One, two,
three, and so on. So actually, we are not printing
it in the matrix style, but we have a nested
four loop that we are making use of to iterate
through the arrays. Okay? If you have a
matrix sort of array, which is an array of arrays, then you can make
use of this kind of a syntax to iterate
through it. All right? So that's about four
loop. Four loop is essentially or loops in general are essentially
useful when you want to repeat a
particular piece of code for a number of times until a
condition is satisfied. So that is where
loops are being used, and four loops just happens
to be a kind of a loop. I hope this was useful.
5. Repeat to Succeed: Mastering While Loops for Dynamic Control: So when we talk about loops, we also have something called a le loops or I
loop, I should say. All right. Now what
is a Ville loop? So Vy loop is a kind of
loop that executes a block of code or a group of
statements over here. As long as the condition
evaluates to true. So once the condition
turns out to be false, then in that case, the le
loop is executed. All right. So let me give you an
example over here of how a le loop would work
in Java script. So let's say you
have this variable, okay, you can have
a Wile statement. What do you want the
condition to be? So let's say, I would
say I is less than five. Okay, I can say Console, dot log over here, and
I can print I like so. Okay. And I'll save this. Another thing is this goes into an endless loop, you
can see over here. Okay. Now, this is not right, because there is no
break condition. The loop is never executed. Loop is never exited. So you should have some sort
of a condition over here. Okay. Let's say I
have this condition, I also need to increment
the value of I. And if I save this, okay, then the loop would get exited. So I just need to
break this now. So now you can see that we have zero to four printed,
which is fine numbers. And last time it went
into so just now, it went into endless loop because we didn't have
to increment condition. Okay? So this is a
syntax of y loop and how it's written
in JavaScript. So that's about Wile oop. It's pretty
straightforward and simple when it comes to
Javascript, right? I hope this was useful.
6. Course Conclusion: And that brings us to the
end of this amazing course. Throughout this course, you
have learned a lot as to how you can make your code much more intelligent so
that it can think, make its own decision, and responsive
throughout, right? We've learned concepts like
if statement, four loops, we've also covered switch, and we also talked about and we've seen
examples of Wil loop. Remember, mastering
control flow is a crucial step in becoming a proficient Ja
Script developer. The skills that you
have built here will empower you to write more dynamic and efficient code as you go and build on
some amazing projects. And it will open door for even more advanced programming
challenges for you. I would encourage you to keep utilizing these concepts
that you have learned in the class so far in your projects that you
build going forward. Because learning and practicing
is the key over here. I would want you to
thank you for being such an engaged and
amazing learner throughout this entire class. With this class, you will find a class project in the project section of
this particular course, which I would encourage
you to complete and submit and share it
with the entire class. That will help you
get some amazing feedback on your project. Happy coding and best of luck on your continued
journey in JavaScript.
Faisal Memon, Product | Engineer | Entrepreneur
