bit-flag-test.js

// Uses bit operation to reduce your codes (by allex)
// GistID: 459aaa91c9b584e127f3f45890026303

const ADD = 4
const UPDATE = 2
const DELETE = 1

const checkFlag = (v, mask) => (v & mask) === mask

const print = (v, desc) => {
  const s = `
  value => ${v} (${desc})
  ADD: ${checkFlag(v, ADD)}, UPDATE: ${checkFlag(v, UPDATE)}, DELETE: ${checkFlag(v, DELETE)}
  `
  console.log(s)
}

// (default) add, update, delete
let flg = ADD | UPDATE | DELETE
print(flg, 'add, update, delete')

// add & update
flg = ADD | UPDATE
print(flg, 'add & update')

// add & delete
flg = ADD | DELETE
print(flg, 'add & delete')

// update & delete
flg = UPDATE | DELETE
print(flg, 'update & delete')