Introduction to TypeScript: The Modern Standard

JavaScript has come a long way, but as applications grow, so does the complexity of maintaining them. This is where TypeScript steps in.

What is TypeScript?

TypeScript is a typed superset of JavaScript that compiles to plain JavaScript. In simple terms, it’s JavaScript with superpowers: it allows you to add static types to your code, helping you catch errors before running the application.

“TypeScript saves you time by catching errors during development, not in production.”

Why use it?

1. Type Safety: Avoid the classic undefined is not a function.
2. Better Autocomplete: Editors like VS Code understand your code better, offering precise suggestions.
3. Safe Refactoring: Renaming a function or variable becomes trivial and safe.
4. Living Documentation: Types act as documentation that never gets outdated.

Basic Concepts

Static Typing

In JS, a variable can change types. In TS, you define what it is:

let firstName: string = "Ivan";
let age: number = 25;
let isDeveloper: boolean = true;

// Error: Type 'number' is not assignable to type 'string'
// firstName = 100; 

Interfaces

Interfaces define the shape of an object, enforcing a contract:

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

function registerUser(user: User) {
  console.log(`Registering ${user.name}`);
}

Conclusion

The learning curve of TypeScript is totally worth it. Once you get used to the safety it offers, going back to pure JavaScript feels like walking a tightrope without a net.

Start by migrating small files to .ts and feel the difference!