class继承写法
class F {
constructor(name){
this.name = name
}
}
class S extends F {
constructor(name, age) {
super(name)
}
}
function的实现方式
const _extends = (() => {
let extendtatics = (() => {
function getStaticsByForIn(s, p) {
for(let key in p) {
if(p.hasOwnProperty(key)) {
s[key] = p[key]
}
}
}
function getStaticsByObjectKeys(s, p) {
Object.keys(p).forEach(key => {
s[key] = p[key]
})
}
function getStaticsByProto() {
s.__proto__ = p
}
return Object.setPrototypeOf || getStaticsByProto || getStaticsByObjectKeys || getStaticsByForIn
})()
return (Son, Parent) => {
if(typeof Parent !== 'function' && Parent !== null) {
new TypeError(`Class extends value ${String(Parent)} is not a constructor`)
}
extendtatics(Son, Parent)
function __() {
this.constructor = Son
}
Son.prototype = Parent === null ? Object.create(Parent) : (__.prototype = Parent.prototype, new __())
}
})()
const F = (function () {
function F(name) {
this.name = name;
}
return F;
}())
const S = (function(_super) {
_extends(S, _super)
function S(name, age) {
let _this = _super.call(this, name) || this
_this.age = age
return _this
}
return S
})(F)
