call()和apply()的区别

var a = function(a,b){

	console.log(a+b);
},

b = {

	c:5,
	d:3
};

a.call(b,1,2);
a.apply(b,[1,2]);

a.call(b,b.c,b.d);

a.call(b,this.c,this.d);