What is the previous generation language of html5?

The previous generation language of html5 is "XHTML 1.0". HTML5 is a language standard released in 2012. Its previous version is "XHTML 1.0" released in 2000; "XHTML 1.0" is a new language optimized and improved on the basis of "HTML4.0", aiming to be based on XML application.

The operating environment of this tutorial: Windows 7 system, HTML5 version, Dell G3 computer.

The previous generation language of html5 is "XHTML 1.0".

Since the early days of the Web, multiple versions of HTML have been developed:

Extensible Hypertext Markup Language (English: eXtensible HyperText Markup Language, XHTML) is a markup language whose expression is similar to Hypertext Markup Language (HTML), but the syntax is more strict. In terms of inheritance relationship, HTML is an application based on Standard Generalized Markup Language (SGML) and is a very flexible markup language, while XHTML is based on Extensible Markup Language (XML), which is a subset of SGML. . XHTML 1.0 became a W3C recommendation on January 26, 2000.

XHTML is an extensible markup language (XML) that plays a role similar to HTML. Therefore, in essence, XHTML is a transition technology that combines some of the powerful functions of XML and most of the simple features of HTML. .

XHTML1.1 is the last independent standard of XHTML, and 2.0 is in the draft stage. XHTML5 is part of the HTML5 standard, and its name has been changed to "HTML5 Serialized as XML" instead of "Extensible HTML".

Background

At the end of 2000, the international W3C organization (World Wide Web Consortium) announced the release of XHTML version 1.0. XHTML 1.0 is a new language optimized and improved on the basis of HTML 4.0, aiming at XML-based applications. XHTML is an enhanced HTML, and XHTML is a more rigorous and purer version of HTML. Its scalability and flexibility will adapt to more needs of future network applications. Although XML has powerful data conversion capabilities and can completely replace HTML, it is still too early to directly adopt XML in the face of thousands of existing websites designed based on HTML language. Therefore, on the basis of HTML4.0, we extended it with XML rules and obtained XHTML. Therefore, the purpose of establishing XHTML is to realize the transition from HTML to XML. The internationally respected WEB standard in website design is based on XHTML applications (commonly known as CSS DIV).

Difference

XHTML is the successor of the current HTML version. HTML grammar requirements are relatively loose, which is more convenient for web page writers, but for machines, the looser the grammar of the language, the more difficult it is to process. For traditional computers, they are still able to be compatible with loose grammar, but For many other devices, such as mobile phones, it is more difficult. Therefore, XHTML, with rules defined by DTD and more stringent grammatical requirements, was produced.

Most common browsers can parse XHTML correctly. Even early browsers, which are a subset of HTML, can parse XHTML. In other words, almost all web browsers are also compatible with XHTML while parsing HTML correctly. Of course, completely transferring from HTML to XHTML still requires a process.

When combined with cascading style sheets (foreign language abbreviation: CSS), XHTML can exert its real power; this enables the separation of style and content, and at the same time, it can organically combine web page code, and in other separate In the file, various XML applications can also be mixed, such as MathML and SVG.

The changes in the transition from HTML to XHTML are relatively small, mainly to adapt to XML. The biggest change is that the document must be well-formed and all tags must be closed, which means that the start tag must have a corresponding end tag. In addition, all tags in XHTML must be lowercase. According to the tradition since HTML 2.0, many people capitalize tags, and the difference between the two is significant. In XHTML, all parameter values, including numbers, must be enclosed in double quotation marks (in SGML and HTML, quotation marks are not necessary. When the content is only numbers, letters and other allowed special characters, quotation marks are not required). All elements, including empty elements, such as img, br, etc., must also be closed. This is achieved by adding a slash at the end of the start tag, such as ,
. Omitting parameters, such as , is not allowed. You must use . The detailed differences between the two can be viewed through the W3C XHTML description.

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