a instanceof B 检测B.prototype是否存在于参数a的原型链上console.log(s instanceof Son);//true console.log(s instanceof Parent);//true
输出
__proto__
function(){}
Function.prototype
Function.__proto__
p
{constructor: ƒ Person()[[Prototype]]: Object}
s
Parent
constructor
let p = new Parent();Son.prototype = Object.create(Parent.prototype);let s = new Son();
Parent{}
Object.__proto__
Object.prototype
null
Object{}
Array/String/Date/Object/Parent等Function的实例
Son
Son.prototype
Parent.prototype
