Following are the user defined data types in Typescript:
- An array is a collection of the same data type. In TypeScript, we can also write arrays of values.
var list : number[] = [1,3,5];
OR
var list : Array <number> = [1,3,5];
A tuple is a data type that includes two sets of values of different data types.
// Declare a tuple
let a: [string, number];
// initialize it
a = ["hi", 8, "how", 5];
- An interface is a structure that acts as a contract in our application and defines the syntax for classes.
interface Calc { subtract (first : number,
second : number) : any
Let Calculator : Calc = {
subtract (first : number, second : number)
{ return first - second; } }
- Classes are used to create reusable components. They act as a template for creating objects.
- Enums are a set of constant methods. TypeScript provides both string-based and numeric-based enums.
- A function is a logical block of code used to organise the program.