What is TypeScript

What is TypeScript

Type script is superset of javascript it compile on top of javascript only.  When Type script comple it will convert to javascript only. We are saying it as type script as it provide the Type safe javascript format. It uses the concept of OOPS and implement the javascript as OOPS based.

e.g. in Javascript we defined variable like;

var v = 20; // We don’t defined the type.

But if you see in type script it will be

var v : number = 20; // We defined the type

Command to install Type Script in node.js

npm install -g typescript

You can download the type script from Microsoft by given below link:

VS2013 :  https://www.microsoft.com/en-us/download/details.aspx?id=48739

VS2015 : https://www.microsoft.com/en-us/download/details.aspx?id=48593

Basic types in Typescript

Basic Data type for Type script

//Boolean

var IsAvilable: boolean = false;

//Number

var Height: number = 6;

//String

var Name: string = "satya";

//Array

var Student: number[] = [1, 2, 3];

// Enum

enum Color { Red = 5, Green, Blue }

//Any

//Defining any type that you don’t know

var value: any = "test";

value = 1;

//Void

//You can use void as the return type like

Defining the Method in Type Script:

The way of defining method in type script.

/// Defining method where return type in void

function IsExist() : void {

    console.log("random stuff");

}

/// Defining method where return type in String

function IsExist(card :  string): string {

    console.log("random stuff");

    return card;

}

Defining A class in Type script

class Myclass {

    private greeting: string; // private varaiable

myMessage: string;

    constructor(greetingmessage: string) {

        this.greeting = greetingmessage;

    }

    greet() {

        console.log("Your Message {0}", this.greeting);

    }

}

Access class;

var g = new Myclass("message");

Passing Optional Parameter in constructor

constructor(greetingmessage: string, Message? : string) {

        this.greeting = greetingmessage;

        this.myMessage = Message;

    }

Defining the Interface in Type Script:

interface iCreater {

    (x: string): string; /// Defining method

    message: string;  /// Defining Property

}

Inheritance in TypeScript

class Vehicle {

    constructor(name: string){ }

    wheel(noofWheel: number) {

        console.log("Number of Wheel :" + noofWheel);

    }

}

class Car extends Vehicle {

    constructor(name: string) {

        //calling the base constructor

        super(name);

    };

    wheel(noofWheel: number) {

        console.log("Number of Car Wheel :" + noofWheel);

        super.wheel(noofWheel);

    }

}

var v = new Car("car");

v.wheel(4);

Defining the namespace for your classes

You need to define the module

module Game.CardSpace {

    class Vehicle {

        constructor(name: string) { }

        wheel(noofWheel: number) {

            console.log("Number of Wheel :" + noofWheel);

        }

    }

}

Getting references of 1.ts file to another 2.ts file

Need to take the reference of 1.ts like

/// <reference path=1.ts' />

And classes defined in the 1.ts or value need to give as export e.g.

module Game.CardSpace {

    // Export keyword make your variable as public

   export enum CardType  { Spades, Hearts, clubs, Diamond };

}

Other feature and implementation of OOPS:

http://www.typescriptlang.org/Handbook