Bit manipulation in Javascript

bit-manipulation.js

function setBitOn(number, bit) {
  return number | 1 << bit;
}

function setBitOff(number, bit) {
  return number & ~(1 << bit);
}

function toggleBit(number, bit) {
  return number ^ 1 << bit;
}

function isBitOn(number, bit) {
  return (number & 1 << bit) === 1 << bit;
}

function isBitOff(number, bit) {
  return (number & 1 << bit) === 0;
}