class Person {constructor(name) {this.name = name;}sayName() {console.log(this.name);}
}let tom = new Person('Tom');
tom.sayName(); //Tom
console.log(tom instanceof Person); //true
console.log(tom instanceof Object); //true
console.log(typeof Person); //function

//不会被提升
let Person = class {constructor(name) {this.name = name;}sayName() {console.log(this.name);}
};

function createPerson(person) {return new person();
}
let tom = createPerson(class {sayHi() {console.log('Hi');}
});
tom.sayHi(); //Hi

let tom = new class {constructor(name) {this.name = name;}sayName() {console.log(`My name is ${this.name}`);}
}('Tom');
tom.sayName();

class Person {constructor(name) {this.name = name;}//这里不能用get phone(){}
    get phone2() {return this.phone;}set phone2(phoneNumber) {this.phone = phoneNumber;}
}
let price = new Person('Price', 112);
price.name = 'Price2';
price.phone = 119;
console.log(`His name is ${price.name} and his phone number is ${price.phone}`);

//静态成员不能被实例访问。你必须通过类本身来使用它们。
class Person {constructor(name) {this.name = name;}sayName() {console.log(this.name)}//等同于Person.whatIs(){}
    static whatIs() {return 'I am a person!';}
}

class Worker extends Person {/*如果在派生类中定义 constructor 则必须使用super()，否则会发生错误。如果你选择不使用 constructor，那么会自动调用 super() 和传入构造函数的参数以创建类的实例*/constructor(name, age) {super(name);this.age = age;}//注意
    syaName() {super.sayName();console.log(`My name is ${this.name}`);}sayAge (){console.log(`I am ${this.age}`)}
}let jimmy = new Worker('Jimmy', 2);
jimmy.sayAge(); //I am 2
jimmy.syaName(); //Jimmy   My name is Jimmy

class MyArray extends Array {
}

    // 导出数据export var color = "red";export let name = "Nicholas";export const magicNumber = 7;// 导出函数export function sum(num1, num2) {return num1 + num1;}     // 导出类export class Rectangle {constructor(length, width) {this.length = length;this.width = width;}} // 此函数为模块私有function subtract(num1, num2) {return num1 - num2;} // 定义一个函数……function multiply(num1, num2) {return num1 * num2;} // ……稍后将其导出export { multiply };

import { identifier1, identifier2 } from "./example.js";

// 完全导入
import * as example from "./example.js";

    export var name = "Nicholas";export function setName(newName) {name = newName;}

import { name, setName } from "./example.js";
console.log(name); // "Nicholas"
setName("Greg");
console.log(name); // "Greg"
name = "Nicholas"; // error

function sum(num1, num2) {return num1 + num2;
}
export { sum as add };

import { add } from "./example.js";

import { add as sum } from "./example.js";

import { sum } from "./example.js";
export { sum }

<!-- this will execute first -->
<script type="module" src="module1.js"></script>
<!-- this will execute second -->
<script type="module">
import { sum } from "./example.js";
let result = sum(1, 2);
</script>
<!-- this will execute third -->
<script type="module" src="module2.js"></script>

<script type="module" async src="module1.js"></script>
<script type="module" async src="module2.js"></script>