SOURCE

Function.prototype.myCall = function (context) {
    const ctx = context || window
    const fn = Symbol('fn');
    ctx[fn] = this;
    const [first, ...args] = arguments;
    ctx[fn](...args);
    delete ctx[fn]
}
Function.prototype.myApply = function (context, args) {
    const ctx = context || window
    const fn = Symbol('fn');
    ctx[fn] = this;
    ctx[fn](...args);
    delete ctx[fn]
}
Function.prototype.myBind = function (context) {
    const fn = this;
    const [first, ...args] = arguments;
    return function () {
        fn.call(context, ...args)
    }
}

var obj = {
    home: '北京'
}

function test(name, age) {
    console.log('名字：', name, '年龄：', age, '住址：', this.home)
}
test.apply(obj, ['小明', 18])
const fn = test.myBind(obj, '小明', 18);
fn(18)