Analyze basic grammar and semantic writing rules of HTML
This article organizes the basic syntax and semantics of HTML and provides examples. Friends who need it can refer to it
DOCTYPE
DOCTYPE(Document Type)
This statement is located at the very beginning of the document, before the html tag. This tag tells the browser which HTML or XHTML specification the document uses.
DTD(Document Type Definition)
The declaration starts with , it is not case sensitive, there is no content in front, if Having other content (except spaces) will cause the browser to turn on quirks mode in IE to render web pages. Public <code>DTD
, the name format is registration // organization // type tag // language, registration refers to whether the organization is registered by the International Organization for Standardization (ISO), + means yes, - means no. Organization is the name of the organization, such as: W3C
. The type is usually DTD. A tag specifies a description of the public text, that is, a unique descriptive name for the referenced public text, which can be followed by a version number. The last language is the ISO 639
language identifier of the DTD language, such as: EN means English, ZH means Chinese. XHTML 1.0 can declare three DTD types. Represents strict version, transitional version, and framework-based HTML document
respectively.
HTML 4.01 strict
HTML 4.01 Transitional
HTML 4.01 Frameset
HTML5 Document Type
<!-- Use Html5 doctype, case-insensitive-->
meta
Declare the character encoding used in the document
Before html5
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> html5 <meta charset="utf-8">
SEO optimization
Title
<title>your title</title>
Page description
<meta name="description" content="your description">
Keywords
<meta name="keywords" content="your keywords">
Web page Author
<meta name="author" content="your name">
Web search engine indexing method
< ;meta name="robots" content="index,follow">
follow Follow the link and analyze the target page. This is the default behavior and can be ignored.
index Index the web page. This is the default behavior and can be ignored.
noodp does not use the Open Directory Project to create content descriptions.
noydir does not use Yahoo Directory to create content descriptions.
noarchive does not allow search engines to display cached versions of content.
cache allows search engines to display cached versions of content.
Nocache does not allow search engines to display cached versions of content.
Tags
define the structure of the document and make the markup of the document more semantic.
html5 demo <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>html5 demo</title> </head> <body> <header> <h1 id="html-nbsp-demo">html5 demo</h1> <nav> <ul> <li>nav1</li> <li>nav2</li> </ul> </nav> </header> <section> <h1 id="article-nbsp-aside">article aside</h1> <article>article</article> <aside>aside</aside> <section> <footer>footer</footer> </body> </html>
tips
html5 tag is more abundant and complete, the p tag seems to have no use, but if If you just want to add a section of style to the document, the p tag will come in handy. The default style of the
tag will be different in different browsers. In order for a web page to have the same effect in different browsers, it is usually necessary to format the tag style first
@charset "utf-8"; html{margin:0;padding:0;border:0}a,abbr,acronym,address,article,aside,blockquote,body,caption,code,dd,del,dfn,dialog,p,dl,dt,em,fieldset,figure,footer,form,h1,h2,h3,h4,h5,h6,header,hgroup,iframe,img,label,legend,li,nav,object,ol,p,pre,q,section,span,table,tbody,td,tfoot,th,thead,tr,ul{margin:0;padding:0;border:0;font-size:100%;font:inherit;vertical-align:baseline}article,aside,details,dialog,figcaption,figure,footer,header,hgroup,menu,nav,section{display:block}body{line-height:1.5;background:#fff}table{border-collapse:separate;border-spacing:0}caption,td,th{text-align:left;font-weight:400;float:none!important}table,td,th{vertical-align:middle}blockquote:after,blockquote:before,q:after,q:before{content:''}blockquote,q{quotes:"" ""}a img{border:none}a{text-decoration:none}:focus{outline:0}
If you want to use the html5 tag in a browser that does not support html5, you need to add a small piece of JavaScript code
<script> document.createElement('header'); document.createElement('nav'); document.createElement('section'); document.createElement('aside'); document.createElement('article'); document.createElement('footer'); </script>
tag Editable properties contenteditable
<article contenteditable></article>
The above is the detailed content of Analyze basic grammar and semantic writing rules of HTML. For more information, please follow other related articles on the PHP Chinese website!

A consistent HTML encoding style is important because it improves the readability, maintainability and efficiency of the code. 1) Use lowercase tags and attributes, 2) Keep consistent indentation, 3) Select and stick to single or double quotes, 4) Avoid mixing different styles in projects, 5) Use automation tools such as Prettier or ESLint to ensure consistency in styles.

Solution to implement multi-project carousel in Bootstrap4 Implementing multi-project carousel in Bootstrap4 is not an easy task. Although Bootstrap...

How to achieve the effect of mouse scrolling event penetration? When we browse the web, we often encounter some special interaction designs. For example, on deepseek official website, �...

The default playback control style of HTML video cannot be modified directly through CSS. 1. Create custom controls using JavaScript. 2. Beautify these controls through CSS. 3. Consider compatibility, user experience and performance, using libraries such as Video.js or Plyr can simplify the process.

Potential problems with using native select on mobile phones When developing mobile applications, we often encounter the need for selecting boxes. Normally, developers...

What are the disadvantages of using native select on your phone? When developing applications on mobile devices, it is very important to choose the right UI components. Many developers...

Use Three.js and Octree to optimize collision handling of third-person roaming in the room. Use Octree in Three.js to implement third-person roaming in the room and add collisions...

Issues with native select on mobile phones When developing applications on mobile devices, we often encounter scenarios where users need to make choices. Although native sel...


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

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Dreamweaver CS6
Visual web development tools

Notepad++7.3.1
Easy-to-use and free code editor

Atom editor mac version download
The most popular open source editor

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft
