重写apply()方法

var obj = {
     
			a: 'xiao',
			b: 'hong'
		}
		
function test(){
     
	console.log(this, arguments);
}
		
Function.prototype.myApply = function(ctx, args){
     
	var ctx = ctx ? Object(ctx) : window;
	
	ctx.originFn = this;
	//如果不是object && fn , 证明是原始值抛出异常
	if(typeof args !== 'object' && typeof args !== 'function'){
     
		throw new TypeError('CreateListFromArrayLike called on non-object');
	}
	
	//不是数组执行原函数
	if(!args || typeOf(args) !== 'Array'){
     
		return ctx.originFn();
	}
	
	var ret = eval('ctx.originFn('+ args +')');
	delete ctx.originFn;
	
	//封装typeof方法
	function typeOf(value){
     
		if(value === 'null'){
     
			return 'null';
		}
		return typeof(value) === 'object' ? {
     
			'[object Object]': 'Object',
			'[object Array]': 'Array',
			'[object Number]': 'Number',
			'[object Boolean]': 'Boolean',
			'[object String]': 'String'
		}[({
     }).toString.call(value)] : typeof(value);
	}
	
	return ret;
}

test.myApply(obj, [1, 2, 4]);