call 与 apply 的区别是 cal 只能一个一个的传递参数,apply 是可以通过数组来传递参数, bind 需要进行一次额外的声明,
call 实例
var arr = {num: 2};
function aa(val1, val2) {
return this.num+val1+val2;
}
console.log(aa.call(arr, 2,3)); // functionname.call(obj, functionArguments)
apply 实例
var obj = {num: 2};
var obj2 = {num: 3};
function add(val1, val2, val3) {
return this.num+val1+val2+val3;
}
var arr = [1,2,3];
console.log(add.apply(obj, arr));
console.log(add.apply(obj2, arr));
bind 实例
var obj = {num: 5};
function add(val1, val2, val3) {
return this.num+val1+val2+val3;
}
var bound = add.bind(obj);
console.log(bound(3,4,5));