What are the differences between interfaces and type aliases in TypeScript?

What are the differences between interfaces and type aliases in TypeScript?

In TypeScript, interfaces and type aliases are both used to define types, but they have some key differences. Interfaces can be extended and implemented, while type aliases cannot. Additionally, interfaces are better suited for defining object shapes, whereas type aliases can represent 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 the structure of an object that will be implemented by a class. For example, if you have a class Car, you might define an interface Vehicle that specifies properties like make, model, and year.

What about type aliases? When should I use them?

Type aliases are useful when you want to create a more complex type, such as a union or a tuple. For instance, you could define a type alias StringOrNumber that can be either a string or a number, which is not something you can do with an interface.

Are there any performance differences between the two?

Generally, there are no significant performance differences between interfaces and type aliases in TypeScript. The choice between them usually comes down to design preferences and specific use cases.