ES6-Class的写法

========1.Class的用法========

class Person{

constructor(name, age){

this.name = name;

this.age = age;

}

say(words){

console.log(`${this.name} is saying ${words}.`);

}

}

let p = new Person('小王', 25);

p.say('hello world');

 

================运行结果====================

 

小王 is saying hello world.

 

 

================分割线====================

========2.立即执行函数的Class========

let p = new class {

constructor(name, age){

this.name = name;

this.age = age;

}

say(words){

console.log(`${this.name} is saying ${words}.`);

// console.log(Person.name);

}

}('小王', 30);

p.say('hello');

 

================运行结果====================

 

 

小王 is saying hello.

 

================分割线====================

========3.class不会进行变量提升，所有的class，必须先定义后使用========

 

console.log(Person);

class Person{

constructor(){

}

}

 

================运行结果====================

 

ReferenceError: Cannot access 'Person' before initialization