What is the difference between TypeScript interfaces and types?

What is the difference between TypeScript interfaces and types?

In TypeScript, both interfaces and types can be used to define the shape of an object, but they have some differences. Interfaces are specifically designed for object shapes and can be extended or implemented, while types can represent any valid TypeScript type, including primitives, unions, and intersections.

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

Sure! Use an interface when you want to define a contract for classes to implement. For example, if you have a class that needs to adhere to a specific structure, an interface is a good choice. On the other hand, if you need to create a union type or a more complex type, using a type alias would be more appropriate.

Are there any performance differences between using interfaces and types?

Generally, there are no significant performance differences between interfaces and types in TypeScript. The choice between them is more about design and readability rather than performance.

Can interfaces be merged in TypeScript?

Yes, interfaces in TypeScript can be merged. If you declare the same interface multiple times, TypeScript will automatically merge them into a single interface, which is useful for extending existing interfaces.