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Hello again, everyone.

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So we're going to start a new lesson, and in this lesson, we'll talk about data types in TypeScript.

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So actually, I think you're probably familiar with this topic from earlier JavaScript and different

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programming languages that you may know already, but in this lesson I want to talk about the intricacies

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of typescript.

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So basically, when we say the data type of a variable, well, the first things that come to mind will

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be values such as string and number and boolean.

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So let's see how these values are defined in typescript and how they're used.

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So now we first use the let key word to define a variable.

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And the name we want to use after, for example, say X here.

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And we put in a call in and the type that we want to specify, so we'll use String as our first example.

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So then we can give the value just by putting equals or we can define it this way and give the value

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later.

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Another way to define it could be.

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Just like we do here.

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We first specified that we will use string data and then we set a value.

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It's now the final variable, why using Aulet key word again.

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And I give a number as the first value well, actually, by doing this, I indicate that I have defined

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a number of variable.

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And if I then go and assign a string value to the variable, why here is TypeScript warning me.

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It tells us that you have defined variable Y as a number, you cannot give a string value and as you

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know, we won't see that warning in JavaScript.

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All right, so that's that's why defining this is important here.

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So why don't we talk about which variables will use?

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All right, so we've already seen that we can use strings and numbers here.

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And we can assign a boolean value.

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And of course, billions will take a.

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Value of true or false?

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We can also define a race.

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So for this, we can make a few different definitions, we can see them if you want to, because you

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know that we can use square brackets in the array definition.

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Of course, we can prepare a string, not just as a number, but in a list.

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So I want to show you another use.

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Now, one type array.

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And to find the array type between the greater than in maths and science.

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Now, here again, assuming we have prepared a series of numbers, the right number here.

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So what if I use a string expression and an array that I define as no in this way?

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Of course, it's going to give us a warning here, because we stated that it's a no ray.

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But if we don't want to make any definitions here, there won't be any warning, as you can see here.

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Cool.

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So there's also a tuple type that allows us to define a different data type array.

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And TypeScript, you can see how.

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All right, so now, while doing the definition, we can specify that the first element in this array

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can be a number in the second element can be a string.

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And here I use number as the initial value, then a string value.

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So at this point, we should pay attention to the element with the index, zero is a number and the

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element with the index is a string.

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So if we move around here, then we get an error.

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So that's why you have to be careful at this point.

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All right, so we can refer to any.

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As another data type.

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So sometimes there may be uncertainty about which data type to use while developing a project.

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So at that point, any data type comes to our rescue.

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And here we just determined the variable using the let keyword while defining then we can define as

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any if we want to or if we don't specify anything here, then we can define different data types later.

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Just like we do here.

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And as you can see, we've defined this way and received no errors.

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But we also know that when we did type assignment.

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We could not give any values like this.

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So as the next variable type, we can refer to ENUM.

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So Inam is a data type that does not have JavaScript, but it comes with TypeScript.

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Allows us to number in more meaningful ways, so I'll show you a small example of colors here.

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So use this data type Inam and then I wrote Colors and.

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I'm typing in a few different colors.

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When we are going to use, like, the red color somewhere here.

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The value returns to us will be zero by default.

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It's now and we define the red variable and call it here, the next value zero.

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For the next couple hours, one.

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And then the next college to.

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As you can see, writing just like this makes it happen.

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So if I add another color in between.

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Of course, these numbers need to change.

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And if we don't want to encounter that kind of situation.

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You do the definition this way.

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So here we can define the number that we want.

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It doesn't have to even be in line.

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If I want to, I can set a value like five for this and three for that.

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Now, where I use them, I'll see five or three as a result.

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Now, if you want to, we can create our JavaScript file and see how this enumeration works.

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And as you remember.

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We were doing this just by running the TSA code in terminal.

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And yep, our jazz file has been created.

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And there you can see the infrastructure that we created in our tax file corresponds to the function

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and J.S..

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And when we look at our other codes, the let key word was replaced with VAR.

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So it's basically the same logic, just a few small changes, so I think that's enough for this lesson.

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What do you say now?

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There are a few more data types that I want to explain, but I don't want to go on too long here.

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We're going to talk about them in the next lesson.

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I'll see you then.

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Good bye for now.