gistfile1.js

function cmpVersion(a,b) {
  var ai, bi;
  if (a.startsWith('.')) a = '0' + a;
  if (b.startsWith('.')) b = '0' + b;
  a = a.split('.');
  b = b.split('.');
  console.log(a,b)
  for (var i=0, l=Math.max(a.length, b.length); i<l; i++) {
    ai = typeof a[i] == 'undefined' ? 0 : parseInt(a[i]);
    bi = typeof b[i] == 'undefined' ? 0 : parseInt(b[i]);
    console.log(ai, bi)
    if (ai < bi) return -1;
    else if (bi < ai) return 1;
  }
  return 0;
};

cmpVersion('1.2.44', '1.2.45'); // -1
cmpVersion('1.6.0.2', '1.6'); // 1