", and it is recommended to use "" ", and it is recommended to use ""
search
HomeWeb Front-endHTML TutorialLearning HTML related specifications

Learning HTML related specifications

Jul 19, 2017 pm 04:43 PM
htmlspecification

Previous words

HTML is a hypertext markup language that describes the structure of web pages. HTML specifications can make HTML code styles consistent, making HTML easier to understand and maintain. This article will introduce the HTML specification in detail

Overall structure

[Page header]

1. The file should end with ".. ...>" starts with the top grid of the first line, it is recommended to use ""

nbsp;html>

 2. The encoding charset of the document must be declared, and it must be consistent with the encoding of the file itself , the meta specifying the character encoding must be the first direct child element of head. It is recommended to use UTF-8 encoding

<meta>

 3. Fill in the appropriate keywords and description

according to the page content and needs
<meta><meta>

4. The page title is an indispensable item. title must be used as a direct child element of head and followed by the charset statement. After that

<meta>页面标题

【Resource introduction】

1. Ensure that favicon is accessible

<link>

2 , There is no need to specify the type attribute when introducing CSS and

JavaScript

3. When introducing CSS, you must specify rel="stylesheet"

<link>

 4. Use link to introduce the css file and place it in the head; use script to introduce the js file and place it at the bottom of the body

5. For mobile environments or web applications designed only for modern browsers, if the URL protocol part referencing external resources is the same as the page, it is recommended to omit the protocol prefix. This is because using protocol-relative URL to introduce CSS will send two requests under IE7/8. Whether to use protocol-relative URL should fully consider the environment for which the page is intended

<script></script>

[Structural Optimization]

 1. Try to follow HTML standards and semantics , but not at the expense of practicality. Try to use the fewest tags and maintain the minimum complexity at all times

2. The structural order and visual order should be basically consistent, and the HTML structure should be written in the visual order from top to bottom and from left to right. Sometimes in order to facilitate search engine crawling, important content will be moved ahead of time in the order of the HTML structure

 3. Separate structure, performance, and behavior and avoid inlining

 4. Each block Level elements start on a new line, and each line is aligned using Tab indentation (child elements of head and body do not need to be indented). Delete redundant end-of-line spaces

5. For tables with relatively simple content, it is recommended to write tr in a single line

6. You can use blank lines to separate large modules so that the modules Clearer

Code format

[Indentation]

Use 4 spaces instead of 1 Tab (can be set in most editors)


  • first
  • second

【Naming】

1. Class must be all lowercase letters, separated by - between words

2. Class must represent the corresponding module or component Content or functions must not be named with style information

<!-- good --><div></div><!-- bad --><div></div>

3. Avoid using the same name and id on the same page. Because the IE7-browser confuses the id and name attributes of elements, document.getElementById may obtain unexpected elements. Therefore, you need to be very careful when naming the id and name attributes of elements. Tags do not need to be self-closing

3. For closing tags that are allowed to be omitted in

HTML5

, omission of closing tags is not allowed

4.

HTML

The use of tags should follow the semantics of the tags and comply with tag nesting rules

<!-- good --><p>Hello StyleGuide!</p><!-- bad --><p>Hello StyleGuide!</p><!-- good --><input><!-- bad --><input><!-- good -->
  • first
  • second
  • first
  • second

[Comments] Use a writing method similar to tag closure, and have a unified format with HTML; Spaces at both ends of the comment copy, the same format as CSS comments

Start comment: (spaces at both ends of the copy)

End comment: (Add "/" symbol before the copy, similar to the closure of a label)

Only the beginning comment is allowed

<!-- 头部 --><div>
<!-- LOGO --><h1 id="a-LOGO-a"><a>LOGO</a></h1>
<!-- /LOGO --><!-- 导航 --><ul>
<li><a>NAV1</a></li>
<li><a>NAV2</a></li>
<!-- 更多导航项 -->
</ul>
<!-- /导航 -->
</div><!-- /头部 -->

[Attribute]

 1. All attributes and values ​​are in lowercase letters

 2. Attribute values ​​must be surrounded by double quotes

 3. For Boolean type attributes, it is recommended not to add attribute values

 4. It is recommended that custom attributes be prefixed with

xxx-

, and it is recommended to use

data-

5. You can omit the type attribute of the style tag and script tag

<!-- good -->
...
...
<!-- good --><script></script><script></script><script></script>【Attribute order】

HTML attributes should appear in a specific order to ensure readability

id
class
name
data-xxx
src, for, type, href
title, alt
aria-xxx, role

 

特殊元素

【图片】

  1、禁止 img 的 src 取值为空,否则会导致部分浏览器重新加载一次当前页面

  2、为图片添加 alt 属性,提高图片加载失败时的用户体验

  3、避免为 img 添加不必要的 title 属性,多余的 title 影响看图体验,并且增加了页面尺寸

  4、为图片添加 width 和 height 属性,以避免页面抖动

<img  src="/static/imghwm/default1.png" data-src="#" class="lazy" alt="Learning HTML related specifications" >

  5、有下载需求的图片采用 img 标签实现,无下载需求的图片采用 CSS 背景图实现

  产品 logo、用户头像、用户产生的图片等有潜在下载需求的图片,以 img 形式实现,能方便用户下载

  无下载需求的图片,比如:icon、背景、代码使用的图片等,尽可能采用 css 背景图实现

【表单】

  1、有文本标题的控件使用 label 标签将其与其标题相关联。最好将控件置于 label 内,以减少不必要的 id

<label><input> 我已确认上述条款</label>

  2、使用 button 元素时必须指明 type 属性值。因为button 元素的默认 type 为 submit,如果被置于 form 元素中,点击后将导致表单提交

<button>提交</button><button>取消</button>

  3、在针对移动设备开发的页面时,根据内容类型指定输入框的 type 属性,能获得友好的输入体验

<input>

【多媒体】

  1、在支持 HTML5 的浏览器中优先使用 audio 和 video 标签来定义音视频元素,并使用退化到插件的方式来对多浏览器进行支持

<audio><source><source><object><embed></embed></object></source></source></audio><video><source><source><object><embed></embed></object></source></source></video>

  2、只在必要的时候开启音视频的自动播放

 

The above is the detailed content of Learning HTML related specifications. For more information, please follow other related articles on the PHP Chinese website!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
HTML: The Structure, CSS: The Style, JavaScript: The BehaviorHTML: The Structure, CSS: The Style, JavaScript: The BehaviorApr 18, 2025 am 12:09 AM

The roles of HTML, CSS and JavaScript in web development are: 1. HTML defines the web page structure, 2. CSS controls the web page style, and 3. JavaScript adds dynamic behavior. Together, they build the framework, aesthetics and interactivity of modern websites.

The Future of HTML: Evolution and Trends in Web DesignThe Future of HTML: Evolution and Trends in Web DesignApr 17, 2025 am 12:12 AM

The future of HTML is full of infinite possibilities. 1) New features and standards will include more semantic tags and the popularity of WebComponents. 2) The web design trend will continue to develop towards responsive and accessible design. 3) Performance optimization will improve the user experience through responsive image loading and lazy loading technologies.

HTML vs. CSS vs. JavaScript: A Comparative OverviewHTML vs. CSS vs. JavaScript: A Comparative OverviewApr 16, 2025 am 12:04 AM

The roles of HTML, CSS and JavaScript in web development are: HTML is responsible for content structure, CSS is responsible for style, and JavaScript is responsible for dynamic behavior. 1. HTML defines the web page structure and content through tags to ensure semantics. 2. CSS controls the web page style through selectors and attributes to make it beautiful and easy to read. 3. JavaScript controls web page behavior through scripts to achieve dynamic and interactive functions.

HTML: Is It a Programming Language or Something Else?HTML: Is It a Programming Language or Something Else?Apr 15, 2025 am 12:13 AM

HTMLisnotaprogramminglanguage;itisamarkuplanguage.1)HTMLstructuresandformatswebcontentusingtags.2)ItworkswithCSSforstylingandJavaScriptforinteractivity,enhancingwebdevelopment.

HTML: Building the Structure of Web PagesHTML: Building the Structure of Web PagesApr 14, 2025 am 12:14 AM

HTML is the cornerstone of building web page structure. 1. HTML defines the content structure and semantics, and uses, etc. tags. 2. Provide semantic markers, such as, etc., to improve SEO effect. 3. To realize user interaction through tags, pay attention to form verification. 4. Use advanced elements such as, combined with JavaScript to achieve dynamic effects. 5. Common errors include unclosed labels and unquoted attribute values, and verification tools are required. 6. Optimization strategies include reducing HTTP requests, compressing HTML, using semantic tags, etc.

From Text to Websites: The Power of HTMLFrom Text to Websites: The Power of HTMLApr 13, 2025 am 12:07 AM

HTML is a language used to build web pages, defining web page structure and content through tags and attributes. 1) HTML organizes document structure through tags, such as,. 2) The browser parses HTML to build the DOM and renders the web page. 3) New features of HTML5, such as, enhance multimedia functions. 4) Common errors include unclosed labels and unquoted attribute values. 5) Optimization suggestions include using semantic tags and reducing file size.

Understanding HTML, CSS, and JavaScript: A Beginner's GuideUnderstanding HTML, CSS, and JavaScript: A Beginner's GuideApr 12, 2025 am 12:02 AM

WebdevelopmentreliesonHTML,CSS,andJavaScript:1)HTMLstructurescontent,2)CSSstylesit,and3)JavaScriptaddsinteractivity,formingthebasisofmodernwebexperiences.

The Role of HTML: Structuring Web ContentThe Role of HTML: Structuring Web ContentApr 11, 2025 am 12:12 AM

The role of HTML is to define the structure and content of a web page through tags and attributes. 1. HTML organizes content through tags such as , making it easy to read and understand. 2. Use semantic tags such as, etc. to enhance accessibility and SEO. 3. Optimizing HTML code can improve web page loading speed and user experience.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
1 months agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. Best Graphic Settings
1 months agoBy尊渡假赌尊渡假赌尊渡假赌
Will R.E.P.O. Have Crossplay?
1 months agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

MinGW - Minimalist GNU for Windows

MinGW - Minimalist GNU for Windows

This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools

ZendStudio 13.5.1 Mac

ZendStudio 13.5.1 Mac

Powerful PHP integrated development environment

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor