Javascript中async与await的捕捉错误详解
时间:2022-07-09 09:35:37|栏目:JavaScript代码|点击: 次
async与await捕捉错误
正常的输出时
<template> <div class="hello"> </div> </template> <script> export default { name: 'HelloWorld', created() { this.init() }, methods: { init() { let p1 = new Promise((resolve) => { setTimeout(() => { resolve(666) }, 1000) }) async function run() { let res = await p1 console.log('res', res) } run() // 正常的调用时候:log输出 666 }, }, } </script>
try catch捕捉错误
<template> <div class="hello"> <h1>{{ msg }}</h1> <p> For a guide and recipes on how to configure / customize this project,<br /> check out the <a href="https://cli.vuejs.org" target="_blank" rel="noopener">vue-cli documentation</a>. </p> <h3>Installed CLI Plugins</h3> <ul> <li><a href="https://github.com/vuejs/vue-cli/tree/dev/packages/%40vue/cli-plugin-babel" target="_blank" rel="noopener">babel</a></li> <li><a href="https://github.com/vuejs/vue-cli/tree/dev/packages/%40vue/cli-plugin-eslint" target="_blank" rel="noopener">eslint</a></li> </ul> <h3>Essential Links</h3> <ul> <li><a href="https://vuejs.org" target="_blank" rel="noopener">Core Docs</a></li> <li><a href="https://forum.vuejs.org" target="_blank" rel="noopener">Forum</a></li> <li><a href="https://chat.vuejs.org" target="_blank" rel="noopener">Community Chat</a></li> <li><a href="https://twitter.com/vuejs" target="_blank" rel="noopener">Twitter</a></li> <li><a href="https://news.vuejs.org" target="_blank" rel="noopener">News</a></li> </ul> <h3>Ecosystem</h3> <ul> <li><a href="https://router.vuejs.org" target="_blank" rel="noopener">vue-router</a></li> <li><a href="https://vuex.vuejs.org" target="_blank" rel="noopener">vuex</a></li> <li><a href="https://github.com/vuejs/vue-devtools#vue-devtools" target="_blank" rel="noopener">vue-devtools</a></li> <li><a href="https://vue-loader.vuejs.org" target="_blank" rel="noopener">vue-loader</a></li> <li><a href="https://github.com/vuejs/awesome-vue" target="_blank" rel="noopener">awesome-vue</a></li> </ul> </div> </template> <script> export default { name: 'HelloWorld', props: { msg: String, }, created() { this.init() }, methods: { init() { let p1 = new Promise((reject) => { setTimeout(() => { reject(new Error('错误了哦')) }, 1000) }) async function run() { try { let res = await p1 console.log('res', res) } catch (error) { console.log('error', error) } } run() // 报错运行 res Error: 错误了哦 }, }, } </script>
多个异步嵌套时
没有try {} catch {} 捕捉错误的
<template> </template> <script> export default { name: 'HelloWorld', props: { msg: String, }, created() { this.init() }, methods: { init() { let p1 = new Promise((resolve) => { setTimeout(() => { // reject(new Error('错误了哦')) resolve(1) }, 1000) }) let p2 = function (arg) { return new Promise((reject) => { setTimeout(() => { console.log('arg', arg) reject(new Error('错误了哦')) }, 1000) }) } async function run() { const res1 = await p1 console.log('res1', res1) // 1 const res2 = await p2(res1) console.log('res2', res2) // res2 Error: 错误了哦 } run() }, }, } </script>
适使用try{} catch {} 捕捉错误的
<template> <div>HelloWorld</div> </template> <script> export default { name: 'HelloWorld', components: {}, data() { return {} }, created() { this.init() }, methods: { init() { let p1 = new Promise((resolve) => { setTimeout(() => { // reject(new Error('错误了哦')) resolve(1) }, 1000) }) let p2 = function (arg) { return new Promise((reject) => { setTimeout(() => { console.log('arg', arg) reject(new Error('错误了哦')) }, 1000) }) } async function run() { try { var res1 = await p1 console.log('res1', res1) } catch (error) { return new Error('error1', error) } try { const res2 = await p2(res1) console.log('res2', res2) } catch (error) { return new Error('error2', error) } } run() }, }, } </script> <style lang="scss" scoped></style>
效果
await-to-js
异步嵌套使用了try,代码相对不够智能
- 特别使用第三方的npm包 await-to-js
- 作用:无需 try-catch 即可轻松处理错误的异步等待包装器
- 下载:
yarn add await-to-js -S
- 使用
<template> <div>HelloWorld</div> </template> <script> import awaitTo from 'await-to-js' export default { name: 'HelloWorld', components: {}, data() { return {} }, created() { this.init() }, methods: { init() { let p1 = new Promise((resolve) => { setTimeout(() => { // reject(new Error('错误了哦')) resolve(1) }, 1000) }) let p2 = function (arg) { return new Promise((reject) => { setTimeout(() => { console.log('arg', arg) reject(new Error('错误了哦')) }, 1000) }) } async function run() { const [err, res1] = await awaitTo(p1) if (err) throw new Error('错误1') console.log('res1', res1) const [err2, res2] = await awaitTo(p2(res1)) if (err2) throw new Error('错误2') console.log('res2', res2) } run() }, }, } </script> <style lang="scss" scoped></style>
效果:
总结
栏 目:JavaScript代码
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