Enum flags in JavaScript

Question

I need to emulate enum type in Javascript and approach seems pretty straight forward:

var MyEnum = {Left = 1; Right = 2; Top = 4; Bottom = 8}

N

Answer 1

You just have to use the bitwise operators:

var myEnum = {
  left: 1,
  right: 2,
  top: 4,
  bottom: 8
}

var myConfig = myEnum.left | myEnum.right;

if (myConfig & myEnum.right) {
  // right flag is set
}

More info:

• Understanding bitwise operations in javascript
• How to check my byte flag?