mkdirnodejs-event-loop-examplecdnodejs-event-loop-example npm init -y 步骤2: 创建 JavaScript 文件 在项目目录中创建一个名为fileReader.js的 JavaScript 文件,然后添加以下代码: constfs =require('fs');// 异步文件读取fs.readFile('example.txt','utf8',(err, data) =>{if(err) {console.error('...
}downloadFile('https://example.com/file.txt') .then(() =>{console.log('File download complete'); }); async/await:async/await是基于Promise的一种更简洁的异步编程模型。通过使用async关键字声明一个函数为异步函数,然后在函数内部使用await关键字等待Promise的结果。 asyncfunctiondownloadFile(url) {return...
//`eventLoop` is an array that acts as a queue队列,先排队的先办理vareventLoop =[ ];varevent;//keep going "forever"while(true) {//perform a "tick"if(eventLoop.length > 0) {//get the next event in the queueevent =eventLoop.shift();//now, execute the next eventtry{ event(); }...
For example, create folder recursively:var fs = require('fs'); var asyncLoop = require('node-async-loop'); var directories = ['test', 'test/hello', 'test/hello/world']; asyncLoop(directories, function (directory, next) { fs.mkdir(directory, function (err) { if (err) { next(err)...
As we’ve seen in the previous example, we would either need to move these values into a higher scope or create a non-semantic array to pass these values on. Array iteration methods You can usemap,filterandreducewith async functions, although they behave pretty unintuitively. Try guessing wh...
callback - The function to call on a later loop around the event loop. Example var call_order = []; async.nextTick(function(){ call_order.push('two'); // call_order now equals ['one','two] }); call_order.push('one')
For example: functionlater(){answer=answer*2;console.log("Meaning of life:",answer);} While the entire contents oflater()would be regarded as a single event loop queue entry, when thinking about a thread this code would run on, there’s actually perhaps a dozen different low-level operati...
» npm run build » cat dist/example.js "use strict" var double = function double(value) { return value * 2 } console.log(double(3)) // <- 6 接下来我们再介绍一个代码检查工具eslint,它可以帮助我们确保项目代码的质量。 2. 使用ESLint提高代码质量和一致性 开发项目时,我们会发现冗余或...
Break up monolithic tasks that may otherwise block the Node.js event loop. For example, if a user request requires CPU intensive work like audio transcoding, you can delegate this task to other processes, freeing up user-facing processes to remain responsive. Provide a reliable communication chann...
{ "plugins": ["transform-async-to-generator"] } 你也可以用env preset的 target 参数"node": "current"替代. 应用程序 Koa 应用程序是一个包含一组中间件函数的对象,它是按照类似堆栈的方式组织和执行的。 Koa 类似于你可能遇到过的许多其他中间件系统,例如 Ruby 的 Rack ,Connect 等,然而,一个关键的设...