How to create fields, constructor and function in TypeScript Class?

What is class in TypeScript?

A class is a template definition of the methods and variables in a particular kind of object. It is extensible program, code and template for creating objects.

A TypeScript is object oriented JavaScript and it also supports object oriented programming features like classes, interfaces, etc.

A class captains the Public, Private, Protected and Read-only modifiers and Public by default.
You can see the below example, the class User and each members are public by default.

Stayed Informed - Object Oriented Programming Concepts (OOPs)

A class definition can contains the following –

1. Fields

2. Constructors

3. Functions

Example – Use of class field, constructor and function i.e.

//Example 1- A simple class based example.
class User { // Calss
    name: string; //field
    constructor(nameTxt: string) { //constructor
        this.name = nameTxt;
    }

    getName() {//function
        return "Hello, " + this.name;
    }
}

let user = new User("Anil");//Creating Instance objects

How Static class in typescript?

We can define a class with static properties i.e.

export class Constants {
    static baseUrl = 'http://localhost:8080/';
    static date = new Date();
}

Ways to declare a nest class structure in typescript?

//Example 1-
declare module a{

    class b {
    }

    module b {
        class c {
        }
    }
}

var clB = new a.b();
var clC = new a.b.c();

//Example 2-
export module a {
    export class b {
    }

    export module b {
        export enum c {
            C1 = 1,
            C2 = 2,
            C3 = 3,
        }
    }
}

//Example 3-
class A {
    static B = class { }
}

var a = new A();
var b = new A.B();

Stayed Informed – Learn Angular 2 with TypeScript

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