Introduction to Interfaces

In TypeScript, an interface is a way to define a contract that an object must adhere to. It specifies a set of properties, methods, and their types that an object must have.

Step 1: Define an Interface

Create a new file called person.ts and add the following code:

interface Person {
  name: string;
  age: number;
}

This code defines an interface called Person with two properties: name and age.

Step 2: Implement the Interface

Add the following code to the person.ts file:

class Employee implements Person {
  name: string;
  age: number;
  constructor(name: string, age: number) {
    this.name = name;
    this.age = age;
  }
}

This code defines a class called Employee that implements the Person interface.

Step 3: Use the Interface

Create a new file called main.ts and add the following code:

const employee: Person = new Employee('John Doe', 30);
console.log(employee.name);
console.log(employee.age);

This code creates a new Employee object and assigns it to a variable of type Person. It then logs the name and age properties of the object to the console.