随着es6的更新与普及新的语法又在es7、es8中推广与更进一步；
es5的同步处理请求的方式：
server.getUser().then((res) => {if (res.status == ‘success‘) {console.log(‘请求成功‘） ???getAddress(res.model.id) //成功后再继续发下一个请求} else { ?????????????console.log(‘请求失败‘) ???????}})function getAddress(userid){ ????server.getAddress({id:userid}).then((res) => {if (res.status == ‘success‘) {console.log(‘请求成功‘） ???//处理逻辑} else { ?????????????console.log(‘请求失败‘) ???????} ?})}点评：此处至少有两个问题
1.代码没有加异常处理，如果接口返回失败或代码质量报错，会造成代码阻塞卡死应用；
2.嵌套发请求太落后已不适应当前前端的发展，造成可读性差；
修改一下用es6 的async awiat
try{ ???let user =awiat getUser(); ???if(user){ ????????let address = awiat getAddress(user.id) ????????//处理逻辑 ???}}catch(e){ ???console.error(e)}//...省略代码 ??上面两个方法报错不会阻塞后面代码的执行//封装两个请求方法async function getUser(){ ????let data = ‘‘; ????return new Promise(async (resolve, reject) => { ?????????try{ //加异常处理 ???????????????data =await server.getUser(); ???????????????if(data.status==‘success‘){ ???????????????????return resolve(data) ???????????????}else{ ??????????????????return resolve(‘‘) ???????????????} ?????????}catch(e){ ??????????????reject(e) ?????????} ???})} ???async function getAddress(id){ ????let data = ‘‘; ????return new Promise(async (resolve, reject) => { ?????????try{ //加异常处理 ???????????????data =await server.getAddress({id:id}); ???????????????if(data.status==‘success‘){ ???????????????????return resolve(data) ???????????????}else{ ??????????????????return resolve(‘‘) ???????????????} ?????????}catch(e){ ??????????????reject(e) ?????????} ???})}
js 新语法 async await的使用
原文地址：https://www.cnblogs.com/suzhen-2012/p/10105557.html