Bitwise Addition of Integers

addBitwise.js

#! /bin/nodejs

function addBitwise (a, b) {
  // if `a` = `3` and `b` = `2`
  let c = 0; // carry over
  // loop while `b` is not equal to zero
  while (b !== 0) {
    // first iteration
    c = a & b; // bitwise AND: 3/0011 AND 2/0010 --> 2/0010
    a ^= b; // bitwise XOR: 3/0011 XOR 2/0010 --> 1/0001
    b = c << 1; // shift left bitwise: 3/0011 --> 6/0110
  }
  return a; // return sum of 3 + 2 = 5
}

console.log(addBitwise(3, 2));
console.log(addBitwise(7, 5));