es6生成器函数实例_异步编程

• yield关键字,使生成器函数执行暂停
• function*生成器函数语法
• iterator.next()迭代器类的方法，获取当前元素，并指向下一个元素
• let声明变量，块级作用域
• setTimeout指定的毫秒数后调用函数

        // 回调地狱setTimeout(() => {console.log(111);setTimeout(() => {console.log(222);setTimeout(() => {console.log(333);}, 3000);}, 2000);}, 1000);//异步回调function one() {setTimeout(() => {console.log(111);iterator.next();}, 1000);}function two() {setTimeout(() => {console.log(222);iterator.next();}, 2000);}function three() {setTimeout(() => {console.log(333);}, 3000);}//生成器函数function * gen(){yield one();yield two();yield three();}// 调用生成器函数let iterator=gen();iterator.next();// 模拟获取 用户数据 订单数据 商品数据function getUsers(){setTimeout(() => {let data='用户数据';// 调用next方法，并且将数据传入iterator.next(data);}, 1000);}function getOrders(){setTimeout(() => {let data='订单数据';iterator.next(data);}, 1000);}function getGoods(){setTimeout(() => {let data='商品数据';iterator.next(data);}, 1000);}//生成器函数function * gen(){let users=yield getUsers();console.log(users);let orders=yield getOrders();console.log(orders);let goods=yield getGoods();console.log(goods);}// 调用生成器函数let iterator=gen();iterator.next();