TypeScript

Installation?

npm install -g typescript

create helloworld.ts

tsc helloworld.ts

your js file associated with ts is generated

Lets take a look at TS homepage

and see an example

How to typescript?

							
var name = 'Lambert';
name = 10 //possible in JS

var name = 'Sijin';
name = 1100 //cannot convert string to number
							
          

Declaration

							
var name:string;

var age:number;

var cars:Array<string> = []

cars[0] = 'toyota'

cars[1] = 9712 // error
							

					

Arguments

							
function setName(name:string, age:number){
	console.log('Age of ' + ' is '+age)
}

setName('Akhil', 15)

setName('Sreenadh', 18)

function getName():string{
	retrun name;
}
							

					

Functions

there are several ways of decleration

Lets explore it as we dive through it

							
var getName = ():string =>{
	return 'Aboobacker';
}
							

					

Objects and Interfaces

Objects we have saw on ES6

Lets see in whats in TS

Interfaces

How can we pass an object as an argument.

								
interface IPerson{
	firstName : string;
	lastName : string;
	sayHi? : () => void; //? says its function is optional
};
function recivePerson(person:IPerson){
	person.sayHi();
}
								

						

Objects

Create an object in TS

									
class Person{
	firstName:string;
	lastName:string;
	constructor(fName:string, lName: string){
		this.firstName = fName;
		this.lastName = lName;
	}

	sayHi():string	{
		return "My Name is "+this.firstName+" "+this.lastName;
	}
}
									

							

Modules

Dont use global vars

Protect js code

your code gets ruined when you try to add 3rd party libs

										
export class Person{
...
	}
										

								

Apart from this

function overloading

Inheritance

Modules

Decorators

blah blah blah...