手写instanceof，判断对象之间关联性

    function instance_of(L,R){
        const baseType = ['string','number','boolean','undefined','null','symbol'];
        if(baseType.includes(typeof L)) { return false }
        let RP = R.prototype;
        let Lp = L.__proto__;
        while(true){
            if(Lp === null){
                return false;
            }
            if(Lp === RP){
                return true;
            }
            Lp = Lp.__proto__;
        }
    }
    function person(name){
        this.name = name;
    }
    var children = new person('小孩');
    console.log(instance_of(children,person));  //true
    console.log(children instanceof person);  //true