SOURCE

// 绑定一个属性
reflect = {
    num: [1,2,3,4],
    get last() {
        return this.num.length > 0 ? this.num[this.num.length - 1] : undefined
    }
}
console.log(reflect.last);

// 绑定一个函数
var express = 'jss'
var obj1 = {
    get [express] () {
        return "a";
    }
}
console.log(obj1.jss);

// 删除该属性的getter
delete reflect.last