What are mandatory properties in TypeScript?

Can you explain what mandatory properties are in TypeScript?

Mandatory properties in TypeScript are properties that must be defined in an object type. They are specified without a question mark in the type definition.

Can you give me an example of a TypeScript interface with mandatory properties?

Sure! Here's an example:

interface User {
  id: number;
  name: string;
  email: string;
}

In this case, id, name, and email are mandatory properties.

What happens if I don't provide a mandatory property?

If you don't provide a mandatory property when creating an object of that type, TypeScript will throw a compilation error, indicating that the property is missing.

Can mandatory properties be optional later?

No, once a property is defined as mandatory in an interface, it cannot be changed to optional. You would need to create a new interface for that.