e-mihaylin

//Extend the String object with toBase64() and fromBase64() functions
String.prototype.toBase64 = function () {
  const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
  let result = '';
  let i = 0;
  while (i < this.length) {
    let a = this.charCodeAt(i++) || 0;
    let b = this.charCodeAt(i++) || 0;
    let c = this.charCodeAt(i++) || 0;

e-mihaylin

const hammingWeight = v => {  
  v = v - (v>>1 & 0x55555555);
  v = (v & 0x33333333) + (v>>2 & 0x33333333);
  return ((v + (v>>4) & 0xF0F0F0F) * 0x1010101) >> 24;
}

e-mihaylin

function SumBigNumbers  (a, b) {
  var res = '', c = 0;
  a = a.split('');
  b = b.split('');
  while (a.length || b.length || c) {
    c += ~~a.pop() + ~~b.pop();
    res = c % 10 + res;
    c = c > 9;
  }
  return res;