 Hi, in this lesson, we're going to talk about primitive types in TypeScript. Okay, let's make a new file. Let's save it as types.ts and let's start talking about primitive types in TypeScript. First type that we have in TypeScript is number type. That number type is very similar with float or double types in a lot of programming languages. For example, cc++, csharp, java and so on. Let's use it in a simple example. Let's define variable x which will be a number and let's put as a variable for example 4.3. You also must notice then in TypeScript and also in Javascript, you do not have integer type of numbers. All numbers are float or double numbers. Okay, the second primitive type in TypeScript is string. You have it in almost all programming languages. Let's use it for example hello variable. Let's make hello variable which will be string and let's populate it with some text. For example, hello world. Okay, the third primitive type is boolean. You also have it in a lot of programming languages. Its value can be just true or false. Let's make a variable as an example. Let's say variable having money. It's boolean type and its value is true or it could be false. And finally we have null type and undefined. We will talk a little bit about them. Let's first talk about undefined type. Let's make new variable. Let's make it for example variable my money. And it's undefined and let's make variable for example my car. And let's say that it's null. A lot of people are confused with undefined and null. How to use them and where to use them. You need to keep an on mind one thing and that is that undefined is a value while null is an object. So if our variable my money is undefined that means that variable have no value. And when we have my car that means that this variable has been assigned to the object but that object is null. So in TypeScript we have five primitive types. First one is a number. Second one is a string. Third one is boolean. And we have also undefined type for working with variables and null type for working with objects. Undefined is when variable has no value and null is when our object is null. That's all in this lesson. Thanks for watching.