亚洲国产日韩欧美一区二区三区,精品亚洲国产成人av在线,国产99视频精品免视看7,99国产精品久久久久久久成人热,欧美日韩亚洲国产综合乱

current location：Home > Technical Articles > Daily Programming > HTML Knowledge

  • What is the difference between async and defer for script tags?
    What is the difference between async and defer for script tags?
    When using async, the script is downloaded asynchronously and executed immediately, and the execution order is not guaranteed. It is suitable for independent scripts; 2. When using defer, the script is downloaded asynchronously but delayed until the HTML parsing is completed and executed in sequence, which is suitable for scripts that rely on DOM or need to be executed in sequence; 3. If there is no attribute, the script will block HTML parsing, affecting performance; therefore, use async for non-critical scripts and use defer for key logic.
    HTML Tutorial . Web Front-end 819 2025-07-29 04:21:22
  • Prefetching Resources with HTML `link rel='prefetch'`
    Prefetching Resources with HTML `link rel='prefetch'`
    rel="prefetch" is an attribute in HTML that indicates that the browser preloads subsequent resources when it is idle. 1. It is implemented by 2. It is suitable for resources that are not needed on the next page, public scripts or fonts, 3. It has lower priority than preload, 4. It is recommended to load only 1 to 2 key resources at a time and pay attention to mobile compatibility.
    HTML Tutorial . Web Front-end 462 2025-07-29 04:19:32
  • Using HTML `doctype` in Modern Web Development
    Using HTML `doctype` in Modern Web Development
    The reason you have to write is to prevent the browser from entering weird mode and make sure the page is rendered correctly in standard mode. Specifically, it includes: 1. The browser can correctly identify HTML5 document types; 2. Avoid inconsistencies in box model calculation, default style and CSS characteristics due to weird patterns; 3. It is part of the HTML5 standard and is simpler, without reference to DTD; 4. In actual development, it is necessary to pay attention to its location, case and correct insertion during server rendering; 5. Most frameworks will automatically process it, but it is still necessary to check whether the doctype exists in manual writing or in specific scenarios.
    HTML Tutorial . Web Front-end 946 2025-07-29 04:19:13
  • HTML for Single Page Applications (SPAs)
    HTML for Single Page Applications (SPAs)
    The HTML structure of a single page application (SPA) needs to pay more attention to the initial loading experience, SEO support and maintainability. 1. The basic structure should be concise and complete, including doctype declaration, html tag, head area (meta tag, title, style sheet and script reference) and mount container div in body; 2. SEO supports dynamically setting title and meta description, and add OpenGraph or TwitterCard meta tags, appropriately add key text content or combine SSR/pre-rendering to improve search engine recognition effect; 3. The first screen optimization can speed up rendering through loading animation, skeleton screen, inline key CSS and using defer/async attributes, as well as
    HTML Tutorial . Web Front-end 269 2025-07-29 04:15:12
  • Understanding HTML Semantics and Document Outline
    Understanding HTML Semantics and Document Outline
    The importance of HTML semantics and document structure is reflected in three aspects: 1. Assistive technology can better understand content, such as screen readers help visually impaired users; 2. SEO is more friendly, and search engines judge the importance of content; 3. The code is clearer and easier to maintain, making it easier for others to understand. A reasonable structure should use HTML5 tags such as, ,,,, and avoid misunderstandings such as multiple or non-cooperating with titles. Title levels should be arranged linearly, each or using titles starting from, avoiding jumps or style-driven hierarchical errors.
    HTML Tutorial . Web Front-end 406 2025-07-29 04:14:32
  • Using `link rel='canonical'` in HTML
    Using `link rel='canonical'` in HTML
    The canonical tag is a tag written in the head part of the HTML page. Its function is to tell search engines which page is the original page, avoid duplicate content issues and concentrate page weights. It declares the source of content in the form it uses, and is often used in the case where multiple parameter variant links in e-commerce websites point to the same main page. When using it, please note: ① It must be placed in the head area; ② It is recommended to use absolute addresses; ③ Support cross-domain use; ④ The content of the pointing page should be highly similar. Common errors include address errors, closed-loop canonical, conflicts with noindex, etc. Suitable usage scenarios include: pages with the same content and only different parameters, articles are published in multiple columns, and different URLs on mobile and desktop versions. Correct application can help search engines improve
    HTML Tutorial . Web Front-end 215 2025-07-29 04:07:32
  • Generating Dynamic HTML Content with JavaScript
    Generating Dynamic HTML Content with JavaScript
    The key to dynamically generating HTML content is to use JavaScript to manipulate the DOM. The main methods include: 1. Use innerHTML to directly insert HTML strings, which are suitable for simple scenarios but need to pay attention to security issues; 2. Create and add elements through createElement and append, which has a clearer structure and is easy to expand; 3. Update content dynamically based on user interaction, such as listening to input events to achieve immediate feedback; 4. Use template strings to improve code readability and maintenance. At the same time, we need to pay attention to XSS protection and performance optimization to ensure that dynamic page updates are safe and efficient.
    HTML Tutorial . Web Front-end 279 2025-07-29 04:07:12
  • What is the difference between the and section?
    What is the difference between the and section?
    "section" has semantics, indicating content grouping with themes, usually including titles, which helps to build a document outline; 2. "Div" has no semantics, only provides packaging for styles or scripts, and does not affect the document structure; 3. "section" should be given priority to express meaningful page areas, and "Div" should be used to deal with layout or visual needs; therefore, when the content forms an independent logical part, "section" should be used, otherwise "Div" can be used to complete style or functional grouping.
    HTML Tutorial . Web Front-end 682 2025-07-29 04:04:31
  • Using the `formenctype` Attribute for Form Data
    Using the `formenctype` Attribute for Form Data
    The formenctype property should be used when you need to specify an encoding type for a specific submit button without affecting the overall form behavior. 1. Usage scenario: When a form has multiple submit buttons, data needs to be sent in different encoding types, such as one button for regular submission and the other for file upload; 2. Supported types: including application/x-www-form-urlencoded (default), multipart/form-data (for file upload) and text/plain (for debugging); 3. Correct usage: Add the formctype to the button with type submit, which only takes effect on the submit button; 4. Notes: It must cooperate with PO
    HTML Tutorial . Web Front-end 186 2025-07-29 04:02:31
  • Where is the best place to put tags in an HTML document?
    Where is the best place to put tags in an HTML document?
    tagsshouldbeplacedbeforetheclosingtagtopreventblockingpagerendering,orinthewithasyncordeferforearlyloading;2.tagsforCSSmustbeinthetoensurestylesloadfirstandavoidunstyledcontent;3.metatags,title,andSEO-relatedtagsbelongintheforproperindexing,encoding,
    HTML Tutorial . Web Front-end 482 2025-07-29 04:01:32
  • The HTML `label` Tag for Form Accessibility
    The HTML `label` Tag for Form Accessibility
    Label improves form accessibility, and its function is to provide clickable labels for input controls and be recognized by assistive technologies. 1. Explicit association: use the for attribute to bind the id of label and input; 2. Implicit wrapping: put input inside the label without for and id; 3. Hide label: use CSS to hide but retain functions. Common misunderstandings include not using labels, replacing placeholder, multiple labels correspond to one input, and not correctly associated with labels and controls. In special cases, it is recommended to keep visually hidden labels to ensure barrier-free access.
    HTML Tutorial . Web Front-end 440 2025-07-29 03:59:01
  • How to implement lazy loading for images in HTML?
    How to implement lazy loading for images in HTML?
    Usetheloading="lazy"attributeontagsfornativelazyloading,supportedinmodernbrowserswithoutJavaScript,butavoiditforabove-the-foldimages.2.Forcustomcontrol,usetheIntersectionObserverAPIwithdata-srctoloadimageswhentheyentertheviewport,addCSStran
    HTML Tutorial . Web Front-end 716 2025-07-29 03:58:41
  • The HTML `progress` Element for Task Progress
    The HTML `progress` Element for Task Progress
    The elements of HTML can be used to display task progress. 1. The basic usage defines the progress range through value and max attributes. 2. When the progress is uncertain, the value can be omitted to enter the uncertain mode. 3. The progress changes can be achieved through JavaScript. 4. The style can be adjusted through CSS, but attention should be paid to browser compatibility. 5. The downgrade should be done in old browsers to ensure compatibility.
    HTML Tutorial . Web Front-end 866 2025-07-29 03:54:22
  • What is the tabindex attribute for?
    What is the tabindex attribute for?
    Thetabindexattributemakeselementsfocusableandcontrolstheirtaborder:1.tabindex="0"addstheelementtothenaturaltaborder,makingitaccessibleviakeyboard;2.tabindex="-1"allowsprogrammaticfocusbutremovesitfromtabflow,usefulfordynamicfocusl
    HTML Tutorial . Web Front-end 235 2025-07-29 03:51:52

Tool Recommendations

jQuery enterprise message form contact code

jQuery enterprise message form contact code is a simple and practical enterprise message form and contact us introduction page code.
form button
2024-02-29

HTML5 MP3 music box playback effects

HTML5 MP3 music box playback special effect is an mp3 music player based on HTML5 css3 to create cute music box emoticons and click the switch button.

HTML5 cool particle animation navigation menu special effects

HTML5 cool particle animation navigation menu special effect is a special effect that changes color when the navigation menu is hovered by the mouse.
Menu navigation
2024-02-29

jQuery visual form drag and drop editing code

jQuery visual form drag and drop editing code is a visual form based on jQuery and bootstrap framework.
form button
2024-02-29

Organic fruit and vegetable supplier web template Bootstrap5

An organic fruit and vegetable supplier web template-Bootstrap5
Bootstrap template
2023-02-03

Bootstrap3 multifunctional data information background management responsive web page template-Novus

Bootstrap3 multifunctional data information background management responsive web page template-Novus
backend template
2023-02-02

Real estate resource service platform web page template Bootstrap5

Real estate resource service platform web page template Bootstrap5
Bootstrap template
2023-02-02

Simple resume information web template Bootstrap4

Simple resume information web template Bootstrap4
Bootstrap template
2023-02-02

Cute summer elements vector material (EPS PNG)

This is a cute summer element vector material, including the sun, sun hat, coconut tree, bikini, airplane, watermelon, ice cream, ice cream, cold drink, swimming ring, flip-flops, pineapple, conch, shell, starfish, crab, Lemons, sunscreen, sunglasses, etc., the materials are provided in EPS and PNG formats, including JPG previews.
PNG material
2024-05-09

Four red 2023 graduation badges vector material (AI EPS PNG)

This is a red 2023 graduation badge vector material, four in total, available in AI, EPS and PNG formats, including JPG preview.
PNG material
2024-02-29

Singing bird and cart filled with flowers design spring banner vector material (AI EPS)

This is a spring banner vector material designed with singing birds and a cart full of flowers. It is available in AI and EPS formats, including JPG preview.
banner picture
2024-02-29

Golden graduation cap vector material (EPS PNG)

This is a golden graduation cap vector material, available in EPS and PNG formats, including JPG preview.
PNG material
2024-02-27

Home Decor Cleaning and Repair Service Company Website Template

Home Decoration Cleaning and Maintenance Service Company Website Template is a website template download suitable for promotional websites that provide home decoration, cleaning, maintenance and other service organizations. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-05-09

Fresh color personal resume guide page template

Fresh color matching personal job application resume guide page template is a personal job search resume work display guide page web template download suitable for fresh color matching style. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-02-29

Designer Creative Job Resume Web Template

Designer Creative Job Resume Web Template is a downloadable web template for personal job resume display suitable for various designer positions. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-02-28

Modern engineering construction company website template

The modern engineering and construction company website template is a downloadable website template suitable for promotion of the engineering and construction service industry. Tip: This template calls the Google font library, and the page may open slowly.
Front-end template
2024-02-28