Typescript By Hitesh(Youtube)¶

Reference Link : Youtube Link

Provides Type Safety¶

Example:

2 + "2" // Outputs: '22' in JavaScript

Typescript helps prevent such issues with type safety.

What does TypeScript do?¶

Static Checking: Catches errors at compile-time instead of runtime.
TypeScript is a development tool; the project still runs in JavaScript.

Installation¶

Refer to the official TypeScript documentation for installation instructions. docs

Running a TypeScript File¶

tsc index.ts

This command compiles the TypeScript file into a JavaScript file (index.js).

Basic Syntax¶

let variableName: type = value;

Type Inference¶

In many cases, TypeScript can infer the type. For example:

let userId = 3; // TypeScript infers 'userId' as a number.

Functions¶

Basic Function¶

function addTwo(num: number): number {     return num + 2; }

Or using an arrow function:

const addTwo = (num: number): number => num + 2;

Objects in Functions¶

function createUser({name: string, isPaid: boolean}): {name: string, price: boolean} {     
    return {name: "harsh", price: false}; 
}

Working with Types¶

You can define types for complex data structures.

type User = {     
        name: string;     
        email: string;     
        isActive: boolean; 
        };  
function createUser(user: User) {     
    // Function logic here 
    }