普通函数中的this指向问题解决方案apply

fang: function () {
        console.log(this.name)
    },
    fun: function () {
        setTimeout( function () {
            this.fang()
        },100);
    }
};
fangfang.fun()

fang: function () {
        console.log(this.name)
    },
    fun: function () {
        setTimeout( function () {
            this.fang()
        }.apply(fangfang),100);
    }
};
fangfang.fun()