function array_udiff_assoc (arr1) {
  // http://kevin.vanzonneveld.net
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // *     example 1: array_udiff_assoc({0: 'kevin', 1: 'van', 2: 'Zonneveld'}, {0: 'Kevin', 4: 'van', 5: 'Zonneveld'}, function (f_string1, f_string2){var string1 = (f_string1+'').toLowerCase(); var string2 = (f_string2+'').toLowerCase(); if (string1 > string2) return 1; if (string1 == string2) return 0; return -1;});
  // *     returns 1: {1: 'van', 2: 'Zonneveld'}
  var retArr = {},
    arglm1 = arguments.length - 1,
    cb = arguments[arglm1],
    arr = {},
    i = 1,
    k1 = '',
    k = '';
  cb = (typeof cb === 'string') ? this.window[cb] : (Object.prototype.toString.call(cb) === '[object Array]') ? this.window[cb[0]][cb[1]] : cb;

  arr1keys: for (k1 in arr1) {
    for (i = 1; i < arglm1; i++) {
      arr = arguments[i];
      for (k in arr) {
        if (cb(arr[k], arr1[k1]) === 0 && k === k1) {
          // If it reaches here, it was found in at least one array, so try next value
          continue arr1keys;
        }
      }
      retArr[k1] = arr1[k1];
    }
  }

  return retArr;
}

array_udiff_assoc({0: 'kevin', 1: 'van', 2: 'Zonneveld'}, {0: 'Kevin', 4: 'van', 5: 'Zonneveld'}, function (f_string1, f_string2){var string1 = (f_string1+'').toLowerCase(); var string2 = (f_string2+'').toLowerCase(); if (string1 > string2) return 1; if (string1 == string2) return 0; return -1;});

{1: 'van', 2: 'Zonneveld'}