async function wait(message, time) { return new Promise((resolve) => setTimeout(resolve(message), time)); } async function execute() { const message = await wait ("hello", 2000); console.log(message); // hello (after 2000 ms) } execute(); ...
function fetchJson(url) {return fetch(url).then(request => request.text()).then(text => {return JSON.parse(text);}).catch(error => {console.log(ERROR: ${error.stack});});}fetchJson('http://example.com/some_file.json').then(obj => console.log(obj));通过 generator 来编写异步代...
async functionreturn await错误的使用方式 ❌ ESLintno-return-await /*eslint no-return-await: "error"*/asyncfunctionfoo() {// ESLint 检查 ✅returnbar(); }asyncfunctionfoo() {// 绕过 ESLint 检查 ❌awaitbar();return; }// This is essentially the same as `return await bar();`, bu...
asyncfunctionfunc(){const a=await asyncFunc();}func().then().catch() 代码语言:shell AI代码解释 asyncfunctionfunc(){try(){const a=await asyncFunc();}catch(error){}} 🍔四、案例 代码语言:shell AI代码解释 asyncfunctionfunc(){console.log('a')const c=await'c'console.log(c)return'd'}...
async function fn() { // return 7大数据类型的值 返回的是成功的promise对象,空return也是 // return 'str'; // return; // 抛出错误,返回的结果是一个失败的 Promise // throw new Error('出错啦!') // 返回的结果如果是一个 Promise 对象: ...
asyncfunctionf() {return'hello world'; } f().then(v=>console.log(v))//"hello world" async函数内部抛出错误,会导致返回的Promise对象变为reject状态。抛出的错误对象会被catch方法回调函数接收到 asyncfunctionf() {thrownewError('出错了');
async def wait_for(fut, timeout, *, loop=None): if loop is None: loop = events.get_event_loop() if timeout is None: return await fut if timeout <= 0: fut = ensure_future(fut, loop=loop) if fut.done(): return fut.result() fut.cancel() raise futures.TimeoutError() waiter ...
但是使用Async/Await的时候,想要终止程序就很简单,那是因为Async/Await语义化很明显,和一般的function的写法类似,想要终端程序的时候,直接return一个值(“”、null、false等)就可以了,实际上就是直接返回一个Promise。具体实例如下所示: letcount =3;consta=async()=>{constresult =awaitdelay(2000);constresult1...
if(error)returnreject(error); resolve(data); }); }); }; const gen=function*(){ const f1=yield readFile('/etc/fstab'); const f2=yield readFile('/etc/shells'); console.log(f1.toString()); console.log(f2.toString()); }; ...
function sleep(ms) { return new Promise((resolve) => { setTimeout(() => { resolve('sleep for ' + ms + ' ms'); }, ms); }); } Step2:定义异步流程,可以将按照需要定制,就像写同步代码那样 async function asyncFunction() { console.time('asyncFunction total executing:'); ...