Building Type-Safe Applications with TypeScript

TypeScript has become an essential tool for modern web development. Let's explore why and how to use it effectively.

Why TypeScript?

TypeScript adds static typing to JavaScript, which provides several benefits:

1. Catch errors early - Find bugs at compile time instead of runtime
2. Better IDE support - Get autocomplete, refactoring, and navigation
3. Self-documenting code - Types serve as inline documentation
4. Easier refactoring - The compiler helps ensure changes are consistent

Basic Types

Here are the fundamental types in TypeScript:

// Primitive types
let name: string = "Arsene";
let age: number = 30;
let isActive: boolean = true;

// Arrays
let numbers: number[] = [1, 2, 3];
let names: Array<string> = ["Alice", "Bob"];

// Objects
interface User {
  id: number;
  name: string;
  email?: string; // Optional property
}

const user: User = {
  id: 1,
  name: "Arsene"
};

Generics

Generics allow you to write reusable, type-safe code:

function identity<T>(arg: T): T {
  return arg;
}

const num = identity<number>(42);
const str = identity<string>("hello");

Best Practices

1. Enable strict mode - Use "strict": true in tsconfig.json
2. Avoid any - Use unknown or proper types instead
3. Use interfaces - Define shapes for your data
4. Leverage type inference - Let TypeScript infer types when obvious

Conclusion

TypeScript is a powerful addition to any JavaScript project. Start small and gradually adopt more advanced features as your team becomes comfortable.