apply，call，bind的用法

Posted 2020-09-29

//改变this指向
var fn1 = {
    add: function() {
        var sum = 0;
        for(var i=0;i<arguments.length;i++) {
            sum += arguments[i];
        }
        console.log(sum);
        return this.name;
    }
};
var fn2 = {
    name: ‘hello world‘
};
fn1.add.apply(fn2, [1,2,3]);
fn1.add.call(fn2, 4,5,6);
(fn1.add.bind(fn2, 7,8,9))();