What are enums in TypeScript and how do they differ from types?

What are enums in TypeScript and how do they differ from types?

Enums in TypeScript are a way to define a set of named constants. They help in creating a collection of related values, making the code more readable. Types, on the other hand, define the shape of data and can be more flexible.

Can you give me an example of how to use enums?

Sure! Here's a simple example:

enum Direction {
    Up,
    Down,
    Left,
    Right
}

let move: Direction = Direction.Up;

This defines an enum called Direction with four possible values.

How do enums compare to union types?

Enums are more structured and can be used to define a set of named constants, while union types allow for more flexibility by letting you define a type that can be one of several types. For example:

type Direction = 'Up' | 'Down' | 'Left' | 'Right';

Are there any performance implications of using enums?

Enums are compiled to objects in JavaScript, which can have a slight performance overhead compared to using simple strings or numbers. However, the difference is usually negligible unless you're working in performance-critical applications.