What are advanced interfaces in TypeScript?

What are advanced interfaces in TypeScript?

Advanced interfaces in TypeScript allow you to define complex types, including optional properties, readonly properties, and index signatures.

Can you give me an example of an advanced interface?

Sure! Here's an example:

interface User {
  id: number;
  name: string;
  email?: string; // optional property
  readonly createdAt: Date; // readonly property
}

What is the purpose of optional and readonly properties?

Optional properties allow you to define properties that may or may not be present, while readonly properties ensure that a property cannot be modified after its initial assignment.

How do index signatures work in interfaces?

Index signatures allow you to define the shape of an object when you don't know the exact property names in advance. For example:

interface StringArray {
  [index: number]: string;
}