var numA = 123, numB = 123;

function hashCodeA(s) {
    for(var i = 0, h = 0; i < s.length; i++)
        h = Math.imul(31, h) + s.charCodeAt(i) | 0;
    return h;
}
 
function hashCodeB(s) {
  return [...s].reduce(
    (hash, c) => (Math.imul(31, hash) + c.charCodeAt(0)) | 0,
    0
  );
}