How can I extend interfaces in TypeScript?

How can I extend interfaces in TypeScript?

In TypeScript, you can extend interfaces using the extends keyword. For example, if you have an interface Person, you can create a new interface Employee that extends Person.

Can you show me a code example?

Sure! Here's a simple example:

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

interface Employee extends Person {
    employeeId: number;
}

In this example, Employee inherits the properties of Person and adds a new property employeeId.

What if I want to add methods to the extended interface?

You can add methods in the same way you add properties. For instance:

interface Employee extends Person {
    employeeId: number;
    getDetails(): string;
}

This adds a method getDetails to the Employee interface.