CODE EXAMPLE FOR TYPESCRIPT

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