TypeScript — Enums

Basic enum

enum Direction {
  Up,
  Down,
  Left,
  Right
}

let dir: Direction = Direction.Up;

String enum

enum Color {
  Red = 'RED',
  Green = 'GREEN',
  Blue = 'BLUE'
}

let color: Color = Color.Red;

Const enum

const enum Status {
  Active = 'ACTIVE',
  Inactive = 'INACTIVE'
}

let status: Status = Status.Active;

Reverse mapping

enum Direction {
  Up,
  Down,
  Left,
  Right
}

console.log(Direction[0]); // "Up"

Computed members

enum FileAccess {
  None,
  Read = 1 << 1,
  Write = 1 << 2,
  ReadWrite = Read | Write
}

Mini Practice

1. Create basic enum
2. Use string enum
3. Create const enum
4. Use reverse mapping

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Continue with Interfaces - Interface definitions.