phpjs/functions/math/max.js

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function max() {
  //  discuss at: http://phpjs.org/functions/max/
  // original by: Onno Marsman
  //  revised by: Onno Marsman
  // improved by: Jack
  //        note: Long code cause we're aiming for maximum PHP compatibility
  //   example 1: max(1, 3, 5, 6, 7);
  //   returns 1: 7
  //   example 2: max([2, 4, 5]);
  //   returns 2: 5
  //   example 3: max(0, 'hello');
  //   returns 3: 0
  //   example 4: max('hello', 0);
  //   returns 4: 'hello'
  //   example 5: max(-1, 'hello');
  //   returns 5: 'hello'
  //   example 6: max([2, 4, 8], [2, 5, 7]);
  //   returns 6: [2, 5, 7]

  var ar, retVal, i = 0,
    n = 0,
    argv = arguments,
    argc = argv.length,
    _obj2Array = function(obj) {
      if (Object.prototype.toString.call(obj) === '[object Array]') {
        return obj;
      } else {
        var ar = [];
        for (var i in obj) {
          if (obj.hasOwnProperty(i)) {
            ar.push(obj[i]);
          }
        }
        return ar;
      }
    }; //function _obj2Array
  _compare = function(current, next) {
    var i = 0,
      n = 0,
      tmp = 0,
      nl = 0,
      cl = 0;

    if (current === next) {
      return 0;
    } else if (typeof current === 'object') {
      if (typeof next === 'object') {
        current = _obj2Array(current);
        next = _obj2Array(next);
        cl = current.length;
        nl = next.length;
        if (nl > cl) {
          return 1;
        } else if (nl < cl) {
          return -1;
        }
        for (i = 0, n = cl; i < n; ++i) {
          tmp = _compare(current[i], next[i]);
          if (tmp == 1) {
            return 1;
          } else if (tmp == -1) {
            return -1;
          }
        }
        return 0;
      }
      return -1;
    } else if (typeof next === 'object') {
      return 1;
    } else if (isNaN(next) && !isNaN(current)) {
      if (current == 0) {
        return 0;
      }
      return (current < 0 ? 1 : -1);
    } else if (isNaN(current) && !isNaN(next)) {
      if (next == 0) {
        return 0;
      }
      return (next > 0 ? 1 : -1);
    }

    if (next == current) {
      return 0;
    }
    return (next > current ? 1 : -1);
  }; //function _compare
  if (argc === 0) {
    throw new Error('At least one value should be passed to max()');
  } else if (argc === 1) {
    if (typeof argv[0] === 'object') {
      ar = _obj2Array(argv[0]);
    } else {
      throw new Error('Wrong parameter count for max()');
    }
    if (ar.length === 0) {
      throw new Error('Array must contain at least one element for max()');
    }
  } else {
    ar = argv;
  }

  retVal = ar[0];
  for (i = 1, n = ar.length; i < n; ++i) {
    if (_compare(retVal, ar[i]) == 1) {
      retVal = ar[i];
    }
  }

  return retVal;
}