继承
class User{
constructor(name,pwd){
this.name=name
this.pwd=pwd
}showName(){
alert(this.name)
}showPwd(){
alert(this.pwd)
}
}var user=new User('LiLei',1233)
user.showName()
user.showPwd()class VipUser extends User{
constructor(name,pwd,level){
super(name,pwd)this.level=level
}showLevel(){
alert(this.level)
}
}var vip=new VipUser('HanMeiMei',23344,4)
vip.showLevel()
静态方法/属性
const users=[];
//该数组将作为User的users属性的初始值class User{
constructor(firstname,lastname,age){
this.firstname=firstname,
this.lastname=lastname,
this.age=age
}getName()
{
return `${this.firstname} ${this.lastname}`
}static insert(firstname,lastname,age)
{
const u=new User(firstname,lastname,age)
User.users.push(u)
return u
}static getOnebyfirstname(firstname)
{
return Users.find(u=>u.firstname===firstname)
}//定义静态方法
static list(query){
return User.users
}//定义静态属性 等效于 static users=users，只是这种写法js暂不支持
static get ['users'](){
return users
}
}
【ES6(面向对象)】等效于
class User{
constructor(firstname,lastname,age){
this.firstname=firstname,
this.lastname=lastname,
this.age=age
}getName()
{
return `${this.firstname} ${this.lastname}`
}static insert(firstname,lastname,age)
{
const u=new User(firstname,lastname,age)
User.users.push(u)
return u
}static getOnebyfirstname(firstname)
{
return Users.find(u=>u.firstname===firstname)
}static list(query){
return User.users
}
}
User.users=[];
