// Custom the Javascript Apply & Call method.

Function.prototype.customApply = function(obj) {
  obj.constructor.prototype['_temp'] = this;
  var argStr = '';
  if(arguments[1]) {
    for(var i = 0; i < arguments[1].length; i++) {
      argStr += ',arguments[1]['+i+']';
    }
    argStr = argStr.slice(1); // Use slice(1) to remove the first ','
  }
  var functionStr = 'obj._temp('+argStr+')';
  var re = eval(functionStr);
  delete obj.constructor.prototype._temp;
  return re;
}

Function.prototype.customCall = function(obj) {
  return this.customApply(obj, Array.prototype.slice.customApply(arguments, [1]));
}

function Cat() {
  this.food = 'fish';
}

Cat.prototype = {
  say: function(param1, param2) {
    console.log('I Love ' + this.food + ', ' + param1 + ', ' + param2);
  }
}

var blackCat = new Cat();
blackCat.say('smallFish', 'bigFish');

// Demo use.
var whiteDog = {food: 'bone'};
Cat.prototype.say.customApply(whiteDog, ['Bone!', 'BONE!!!']);
Cat.prototype.say.customCall(whiteDog, 'smallBone', 'bigBone');

// Unit test maybe.
function test() {
  var t = Array.prototype.slice.customCall(arguments, 1);
  console.log(t);
}
test(1, 2, 3);