3.async/await: 很多人说async/await是异步编程的终极解决方案、 JavaScript 的 async/await 实现,离不开 Promise。 varsuperagent=require('superagent')functiondelay(){returnnewPromise(function(resolve,reject){setTimeout({resolve(42); },3000); }) }asyncfunctiongetAllBooks(){varbookIDs=awaitsuperagent.ge...
1.callback function foo(callback){//定义函数的时候将另一个函数(回调函数)作为参数传入定义的函数中。 $ajax({ //... success:callback//异步操作执行完毕后,再执行该回调函数,确保回调在异步操作之后执行。 }); } function myCallback(result){ //... } foo(myCallback); 回调函数本身是我们约定俗...
在浏览器的事件循环中,把任务划分为 Task、Microtask,在 Node.js 中是按照阶段划分的,上面我们介绍了 Node.js 事件循环的 6 个阶段,给用户使用的主要是 timer、poll、check、close callback 四个阶段,剩下两个由系统内部调度。这些阶段所产生的任务,我们可以看做 Task 任务源,也就是常说的 “Macrotask ...
function someAsyncOperation(callback) { // 假设这个读取将用耗时95ms fs.readFile('/path/to/file', callback); } const timeoutScheduled = Date.now(); setTimeout(() => { const delay = Date.now() - timeoutScheduled; console.log(`${delay}ms have passed since I was scheduled`); }, ...
const fs = require('fs'); function someAsyncOperation(callback) { // Assume this takes 95ms to complete fs.readFile('/path/to/file', callback); } const timeoutScheduled = Date.now(); setTimeout(() => { const delay = Date.now() - timeoutScheduled; console.log(`${delay}ms have...
function someAsyncOperation(callback) { // Assume this takes 95ms to complete fs.readFile('/path/to/file', callback); } const timeoutScheduled = Date.now(); setTimeout(() => { const delay = Date.now() - timeoutScheduled;
constfs=require('fs');functionsomeAsyncOperation(callback){// Assume this takes 95ms to completefs.readFile('/path/to/file',callback);}consttimeoutScheduled=Date.now();setTimeout(()=>{constdelay=Date.now()-timeoutScheduled;console.log(`${delay}ms have passed since I was scheduled`);}...
async/await方法:loopWithIntervalAsync函数是一个异步函数,它使用for循环来迭代,并在每次迭代后使用await delay(interval)来暂停执行,直到定时器到期。这种方法代码更加简洁,且易于理解和维护。 应用场景 这种间隔执行的循环在需要定时执行任务的场景中非常有用,例如: ...
console.info('FeatureAbility.callAbility async result ' + JSON.stringify(value));})console.info('FeatureAbility.callAbility end' + JSON.stringify(action));在ServiceAbility的onRemoteRequest中增加Log输出,并sleep 1秒种,以便观察线程情况与之间关系:@Override public boolean onRemoteRequest(int code, ...
const fs = require('fs'); function someAsyncOperation(callback){ //Assume this takes 95ms to complete fs.readFile('/path/to/file',callback); } const timeoutScheduled = Date.now(); setTimeout(()=>{ const delay = Date.now() - timeoutScheduled; console.log(`${delay}ms have passed...