From all the promises you enter into it, it creates a new promise which then waits for each promise to finish, before continuing. That ultimately means you can wait for multiple things to finish before you fire something else. This method is particularly useful for UI development - for ...
const wait = (ms) => new Promise((resolve) => setTimeout(resolve, ms)); const asyncFn = async () => { await wait(1000); console.log('Waiting for an asynchronous function to finish executing'); }; asyncFn(); 11、有条件地在对象中添加属性 const isValid = false; const age = 18...
The callback function passed to forEach will get exectuted for each item in the array, so three times in this case. The callback function will get called synchronously so the code below forEach will wait for forEach to complete before it’s exectectued. Everything happens in order and ...
var promise2 = rp('https://api.example.com/endpoint2'); // Currently, both requests are fired, concurrently and // now we'll have to wait for them to finish //现在,两个请求都被执行,必须等到他们执行完成 var response1 = await promise1; var response2 = await promise2; return respo...
functionfetchMessages(username){returnfetch(`https://example.com/api/messages/${username}`).then(response=>response.json());}functiongetUsername(person){returnperson.username;}functionchainedFetchMessages(p,username){// In this function, p is a promise. We wait for it to finish,// then run ...
// In this function, p is a promise. We wait for it to finish, // then run fetchMessages(). const obj = await p; const data = await fetchMessages(username); return { ...obj, [username]: data}; } const msgObj = userList ...
如果你想并行下载mods而不是一次下载一个，run()函数应该是这样的：
Javascript数组方法中,相比map、filter、forEach等常用的迭代方法,reduce常常被我们所忽略,今天一起来探究一下reduce在我们实战开发当中,能有哪些妙用之处,下面从reduce语法开始介绍。 语法 代码语言:txt 复制 array.reduce(function(accumulator, arrayElement, currentIndex, arr), initialValue) ...
We wait for all requests to finish withPromise.all. After completion, we go through the array of responses and server name and response status. $ node main.js http://webcode.me -> nginx/1.6.2: 200 https://example.com -> ECS (dcb/7ECA): 200 ...
We wait for it to finish, // then run fetchMessages(). const obj = await p; const data = await fetchMessages(username); return { ...obj, [username]: data};}const msgObj = userList .map(getUsername) .reduce(chainedFetchMessages, Promise.resolve({})) .then(console.log);// {gles...