es6的新特性和如何使用

let 和 const 声明变量

let a = 1; const b = 2;

箭头函数

const sum = (a, b) => a + b;

模板字符串

const name = 'World'; console.log(`Hello ${name}`);

 

解构赋值

const { name, age } = person;

 

默认参数值

function greet(name = 'World') { console.log(`Hello ${name}`); }

扩展运算符

const arr1 = [1, 2, 3]; const arr2 = [4, 5, 6]; const arr3 = [...arr1, ...arr2];

 

类和继承

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`);
  }
}

const dog = new Dog('Rufus');
dog.speak();

模块化

// module.js export const sum = (a, b) => a + b; 
// main.js import { sum } from './module.js'; console.log(sum(1, 2));