How to compare Unicode strings in Javascript?

Question

When I wrote in JavaScript \"Ł\" > \"Z\" it returns true. In Unicode order it should be of course false. How to fix this? My site i

Answer 1

Mic's code improved for non-mentioned chars:

var alpha = function(alphabet, dir, caseSensitive){
  dir = dir || 1;
  function compareLetters(a, b) {
    var ia = alphabet.indexOf(a);
    var ib = alphabet.indexOf(b);
    if(ia === -1 || ib === -1) {
      if(ib !== -1)
        return a > 'a';
      if(ia !== -1)
        return 'a' > b;
      return a > b;
    }
    return ia > ib;
  }
  return function(a, b){
    var pos = 0;
    var min = Math.min(a.length, b.length);
    caseSensitive = caseSensitive || false;
    if(!caseSensitive){
      a = a.toLowerCase();
      b = b.toLowerCase();
    }
    while(a.charAt(pos) === b.charAt(pos) && pos < min){ pos++; }
    return compareLetters(a.charAt(pos), b.charAt(pos)) ? dir:-dir;
  };
};

function assert(bCondition, sErrorMessage) {
      if (!bCondition) {
          throw new Error(sErrorMessage);
      }
}

assert(alpha("bac")("a", "b") === 1, "b is first than a");
assert(alpha("abc")("ac", "a") === 1, "shorter string is first than longer string");
assert(alpha("abc")("1abc", "0abc") === 1, "non-mentioned chars are compared as normal");
assert(alpha("abc")("0abc", "1abc") === -1, "non-mentioned chars are compared as normal [2]");
assert(alpha("abc")("0abc", "bbc") === -1, "non-mentioned chars are compared with mentioned chars in special way");
assert(alpha("abc")("zabc", "abc") === 1, "non-mentioned chars are compared with mentioned chars in special way [2]");