Web Front-end
JS Tutorial
Do JavaScript's script code blocks belong to macro tasks? What is its execution mechanism and output order?
Do JavaScript's script code blocks belong to macro tasks? What is its execution mechanism and output order?
In-depth discussion on the execution mechanism and output order of JavaScript script code blocks
script code block execution mechanism in JavaScript often raises questions about macro tasks and micro tasks, especially when predicting the order of code execution. This article will explore this issue in depth.
script code block: synchronous execution instead of macro task queue
Many materials classify script code blocks as macro tasks, but this is not entirely accurate. The execution of script code blocks is closer to synchronous execution than typical macro tasks. Let's analyze the following code:
console.log('script1');
Promise.resolve().then(() => { console.log('promise1'); });
console.log('script2'); If script code block is considered a macro task, the expected output order should be:
<code>script1 promise1 script2</code>
However, the actual output is:
<code>script1 script2 promise1</code>
The reason is: the browser parser is encountering
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1359
52
How to correctly display the locally installed 'Jingnan Mai Round Body' on the web page?
Apr 05, 2025 pm 10:33 PM
Using locally installed font files in web pages Recently, I downloaded a free font from the internet and successfully installed it into my system. Now...
Why does negative margins not take effect in some cases? How to solve this problem?
Apr 05, 2025 pm 10:18 PM
Why do negative margins not take effect in some cases? During programming, negative margins in CSS (negative...
How to implement a custom theme by overriding the SCSS variable of Element?
Apr 05, 2025 pm 01:45 PM
How to implement a custom theme by overriding the SCSS variable of Element? Using Element...
How to customize the resize symbol through CSS and make it uniform with the background color?
Apr 05, 2025 pm 02:30 PM
The method of customizing resize symbols in CSS is unified with background colors. In daily development, we often encounter situations where we need to customize user interface details, such as adjusting...
Why do you need to call Vue.use(VueRouter) in the index.js file under the router folder?
Apr 05, 2025 pm 01:03 PM
The necessity of registering VueRouter in the index.js file under the router folder When developing Vue applications, you often encounter problems with routing configuration. Special...
How to use CSS and Flexbox to implement responsive layout of images and text at different screen sizes?
Apr 05, 2025 pm 06:06 PM
Implementing responsive layouts using CSS When we want to implement layout changes under different screen sizes in web design, CSS...
The text under Flex layout is omitted but the container is opened? How to solve it?
Apr 05, 2025 pm 11:00 PM
The problem of container opening due to excessive omission of text under Flex layout and solutions are used...
How to properly introduce index.css file of Element UI and avoid style loading failures?
Apr 05, 2025 pm 02:33 PM
Best practices about the introduction of ElementUI style files Many developers are using Element...
