把window.setTimeout赋值给自定义对象，使用时会报错

Question

var obj = {};
obj.setTimeout = window.setTimeout;

obj.setTimeout(function(){
    console.log("111")
},100);

//Uncaught TypeError: Illegal invocation at <anonymous>:5:5

window下的一些方法，赋值给自定义对象会报错，想知道具体原因。

Answer 1

估计是 this 的问题

使用这个试试

obj.setTimeout = window.setTimeout.bind(window)

Answer 2

var obj = {};
obj.setTimeouts = window.setTimeout;
console.log(obj.setTimeout === window.setTimeout)
obj.setTimeouts(function(){
    console.log("111");
}.call(window),100);

Answer 3

var obj = {};

obj.timeout = function(fn,time) {
    window.setTimeout(fn.bind(this),time)
}

obj.timeout(() => {
    console.log("666");
},100)