es6 class类

class类

class Person {
constructor(name, age, job) {
this.name = name;
this.age = age;
this.job = job;
this.friends = [‘Shelby’,’Court’];
}
sayName () {
console.log(this.name);
}
}
let person = new Person(‘张三’,26,’司机’);
person.sayName();

2.静态方法：
class Point {
constructor(x, y) {
this.x = x;
this.y = y;
}

static distance(a, b) \{    
    const dx = a.x - b.x;    
    const dy = a.y - b.y;    
    return Math.sqrt(dx\*dx + dy\*dy);    
\}

}

const p1 = new Point(5, 5);
const p2 = new Point(10, 10);

console.log(Point.distance(p1, p2));

3.ES6明确规定，Class内部只有静态方法，没有静态属性，但可以用另外方式解决
class Foo {
}
Foo.prop = 1;
Foo.prop // 1

//—-单例模式
class Cache {
static getInstance() {
if (!Cache.instance) {
Cache.instance = new Cache();
}
return Cache.instance;
}
}

var cache = Cache.getInstance();

4.继承：
class Animal {
constructor(name) {
this.name = name;
}

  speak() \{    
    console.log(this.name + ' makes a noise.');    
  \}    
\}

class Dog extends Animal {
speak() {
console.log(this.name + ‘ barks.’);
}
}
let dog = new Dog(‘旺财’);
dog.speak();

//—————————-vue中loginbean的单例模式—————————————
class LoginBean {
static getInstance() {
if (!LoginBean.instance) {
LoginBean.instance = new LoginBean();
}
return LoginBean.instance;
}
constructor() {
this.id = 0;
this.nicheng = null;
}
}

var loginbean = LoginBean.getInstance();
export default loginbean;