xgqfrms™, xgqfrms® : xgqfrms's offical website of GitHub!

js 如何打印出 prototype 的查找路径

Function

function func (name) {
  this.name = name || `default name`;
}

f = new func();
// func {name: "default name"}

// 在 prototype 上添加属性/方法
func.prototype.level1 = 1;
// 1
Function.prototype.level2 = 2;
// 2
Object.prototype.level3 = 3;
// // 3

func.level1;// 访问不到 func.prototype, 因为func 不会查找自己的 prototype, 只会通过 __proto__ 去查找上一级的 prototype 对象
// undefined
func.level2;// 访问到 Function.prototype, 构造函数既可以访问到 Function 也可以访问到 Object
// 2
func.level3;// 访问到 Object.prototype
// 3

f.level1;// 访问到 func.prototype
// 1
f.level2;// 访问不到 Function.prototype
// undefined
f.level3;// 访问到 Object.prototype
// 3

// null, 找不到返回 undefined
f.level4;
// undefined
func.level4;
// undefined

Object

obj = {
  name: "default name",
};

o = new Object;
// {}
o = new Object();
// {}

js & object & prototype & proto & prototype chain

https://www.cnblogs.com/xgqfrms/p/11363819.html

https://hackernoon.com/understand-nodejs-javascript-object-inheritance-proto-prototype-class-9bd951700b29

prototype & proto

Object.proto

Function & Object.proto

Object & Function

https://programmer.help/blogs/javascript-prototype-inheritance.html

refs

MDN

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Inheritance_and_the_prototype_chain

https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Inheritance_and_the_prototype_chain

https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Objects/Object_prototypes

Blogs

https://www.cnblogs.com/xgqfrms/p/13340673.html

https://zhuanlan.zhihu.com/p/87667349

https://programmer.help/blogs/javascript-prototype-inheritance.html

---

---

©xgqfrms 2012-2020

www.cnblogs.com 发布文章使用：只允许注册用户才可以访问！

---