const axios = require('axios');// `axios.get()` returns a promise representing an HTTP request.const promise = axios.get('https://httpbin.org/get?answer=42');// The `then()` function lets you register a callback that JavaScript// will call when the HTTP request succeeds.promise.then...
* @param {Array} iterable Array of functions that returns a promise * @param {Object} concurrency max number of parallel promises running */ function promiseAllThrottled(iterable, { concurrency = 3 } = {}) { const promises = []; function enqueue(current = 0, queue = []) { // return...
//a generic function that displays an alertfunctionpopup(message) {alert(message); }//A function that takes two parameters, the last one a callback functionfunctiongetContent(content, callback) {callback(content);//call the callback function}getContent("JavaScript is awesome!", popup); 正如...
Write a JavaScript program that wraps a callback-based asynchronous function into a promise-returning function. Write a JavaScript function that converts a Node.js style asynchronous function into one that returns a promise. Write a JavaScript program that demonstrates the conversion of setTimeout ...
constaxios=require('axios');// `axios.get()` returns a promise representing an HTTP request.constpromise=axios.get('https://httpbin.org/get?answer=42');// The `then()` function lets you register a callback that JavaScript// will call when the HTTP request succeeds.promise.then(res=>{...
与回调相比,Promise具有许多优点,例如: 让异步代码更易于阅读。 提供组合错误处理。 * 更好的流程控制,可以让异步并行或串行执行。 回调更容易形成深度嵌套的结构(也称为回调地狱)。 如下所示: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 a(()=>{b(()=>{c(()=>{d(()=>{// and so on .....
executorFunction() 被传给这个构造函数,这个函数参数有两个参数 resolve 和 reject 如果someCondition 的计算结果为 true,调用 resolve() 反之,则调用 reject() 这段代码是基于一个简单的条件判断,实际应用时,promise会基于异步操作返回的结果来决定最后的操作。
If the promise returns successfully, theresolve()function is called. And, if an error occurs, thereject()function is called. Let's suppose that the program below is an asynchronous program. Then the program can be handled by using a promise. ...
Well, the good news is that any function that returns a promise can be used with async/await. I’m not saying that we should async/await all the things (this syntax does have its downsides, as we’ll see when we get on to error handling), but we should be aware that this is poss...
/** * Adds two numbers. * @customfunction * @param first First number. * @param second Second number. * @returns The sum of the two numbers. */functionadd(first, second){returnfirst + second; } JSDoc 代码批注说明 代码批注中的 JSDoc 标记用于生成将自定义函数描述到 Excel 的 JSON 元数...