Data types in TypeScript

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


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.


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;

This article is attributed to GeeksforGeeks.org

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