AdvancedProgrammingintermediate

Interfaces

Relax. We'll talk through this in plain words — no textbook voice.

Interface is a powerful way to define the shape of an object. It sets a "contract" for exactly which properties and methods an object must have.

typescript

interface User {
  name: string;
  id: number;
  is_admin?: boolean; // Optional property
}

function printUser(user: User) {
  console.log(`User: ${user.name} (ID: ${user.id})`);
}

let myUser: User = { name: "Alice", id: 123 };
printUser(myUser);

You should see

User: Alice (ID: 123)