Whenever a variable is created, the intention is to assign some value to that variable but what type of value can be assigned to that variable is dependent upon the datatype of that Variable. In typeScript, type System represents different types of datatypes which are supported by TypeScript. The data type classification is as given below:
Built-in Datatypes: TypeScript has some pre-defined data-types-
| Built-in Data Type | keyword | Description |
|---|---|---|
| Number | number | It is used to represent both Integer as well as Floating-Point numbers |
| Boolean | boolean | Represents true and false |
| String | string | It is used to represent a sequence of characters |
| Void | void | Generally used on function return-types |
| Null | null | It is used when an object does not have any value |
| Undefined | undefined | Denotes value given to uninitialized variable | Any | any | If variable is declared with any data-type then any type of value can be assigned to that variable |
Examples:
let a: null = null;let b: number = 123;
let c: number = 123.456;
let d: string = ‘Geeks’;
let e: undefined = undefined;
let f: boolean = true;
let g: number = 0b111001; // Binary
let h: number = 0o436; // Octal
let i: number = 0xadf0d; // Hexa-Decimal
User-defined Data Types: Apart from built-in data types, user can also define its own data type. User-defined types include Enumerations (enums), classes, interfaces, arrays, and tuple.
NOTE: In built-in data types, any is a special data-type, also the super data-type of all data types. If a variable is declared with any data type then we can assign any type value to that variable.
Examples:
let a: any = null;let b: any =123;
let c: any = 123.456;
let d: any = ‘Geeks’;
let e: any = undefined;
let f: any = true;
