What is the difference between interface and type alias in TypeScript?

What is the difference between interface and type alias in TypeScript?

In TypeScript, both interfaces and type aliases can be used to define types, but they have some differences. Interfaces are primarily used for defining the shape of objects, while type aliases can define any type, including primitives, unions, and tuples.

Can you give me an example of when to use an interface?

Sure! Use an interface when you want to define a contract for an object, like this:

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

And when should I use a type alias instead?

You might use a type alias when you need to create a union type or a more complex type. For example:

type ID = string | number;

Are there any performance differences between the two?

No, there are no significant performance differences between interfaces and type aliases. The choice is mostly about readability and use case.