TYPESCRIPT

enums in typescript

enum Direction {
  Up = 1,
  Down,
  Left,
  Right,
}

typescript enum

enum Sides {LEFT, RIGHT};
Sides.LEFT;  // 0
Sides.RIGHT; // 1

const typeFromEnum: Sides.LEFT = Sides.LEFT; // Enums become types!

console.log(Sides);   // { '0': 'LEFT', '1': 'RIGHT', LEFT: 0, RIGHT: 1 } 

type leftOrRight = keyof typeof Sides; // 'LEFT' | 'RIGHT'

let sideName: string = Sides[0];  // 'LEFT'  reverse mapping


enum EnumWithString {
  X = "XX",
  Y = "YY",
};
console.log(EnumWithString); // { X: 'XX', Y: 'YY' }  no reverse mapping

TypeScript enum

enum Direction {
  Up = 1,
  Down,
  Left,
  Right,
}
We’ll first start off with numeric enums, which are probably more familiar if you’re coming from other languages. An enum can be defined using the enum keyword.

If we wanted, we could leave off the initializers entirely:
enum Direction {
  Up,
  Down,
  Left,
  Right,
}
  
enum Direction {
  Up = "UP",
  Down = "DOWN",
  Left = "LEFT",
  Right = "RIGHT",
}

typescript enum

enum EMoney {
	gopay = 'gopay',
	dana = 'dana',
	ovo = 'ovo'
}

enum Bank {
	bca = 'bca',
	mandiri = 'mandiri',
	bri = 'bri'
}

interface OnlineShop<T> {
	payment: T
}

const payment: OnlineShop<Bank> = {
	payment: Bank.bca
}