Created At: 2/15/2025

TypeScript: A Statically Typed JavaScript Superset

Introduction

TypeScript is an open-source programming language developed by Microsoft. It is a superset of JavaScript that adds static typing, making code more reliable, scalable, and maintainable.

Why Use TypeScript?

1. Static Typing

TypeScript enables static type checking, which helps catch errors during development rather than runtime.

2. Improved Code Readability

With explicit types, TypeScript makes the code more understandable and easier to maintain.

3. Better Developer Experience

Features like IntelliSense, auto-completion, and better error detection improve productivity.

4. Object-Oriented Programming (OOP) Support

TypeScript includes features like interfaces, generics, and access modifiers, making it ideal for large-scale applications.

5. Compatibility with JavaScript

Since TypeScript is a superset of JavaScript, existing JavaScript code can be gradually migrated to TypeScript.

Installing TypeScript

To install TypeScript globally, run:

npm install -g typescript

To check if TypeScript is installed:

tsc --version

TypeScript Basics

Variables & Types

let name: string = "John";
let age: number = 30;
let isDeveloper: boolean = true;

Functions with Type Annotations

function greet(name: string): string {
return `Hello, ${name}!`;
}
console.log(greet("Alice"));

Interfaces

Interfaces define object structure:

interface User {
id: number;
name: string;
isAdmin: boolean;
}

const user: User = { id: 1, name: "John", isAdmin: true };

Classes

class Person {
constructor(private name: string, private age: number) {}
introduce(): string {
return `My name is ${this.name} and I am ${this.age} years old.`;
}
}
const person = new Person("Alice", 25);
console.log(person.introduce());

Generics

Generics allow reusable code:

function identity(value: T): T {
return value;
}
console.log(identity("Hello"));
console.log(identity(42));

TypeScript Configuration

Create a tsconfig.json file for project configuration:

{
"compilerOptions": {
"target": "ES6",
"module": "CommonJS",
"strict": true,
"outDir": "./dist"
}
}

Compile TypeScript files using:

tsc

Conclusion

TypeScript enhances JavaScript by adding static typing, improving code quality, and enabling better tooling. Whether you're working on a small project or a large-scale application, TypeScript provides significant benefits.