A brief discussion of the differences between HTML5 and HTML4

After the release of HTML 4.01 in December 1999, the subsequent HTML5 and other standards were shelved. In order to promote the development of the Web standardization movement, some companies joined forces and established a group called the Web Hypertext Application Technology Working Group ( Web Hypertext Application Technology Working Group-WHATWG) organization. So what are the changes between them from HTML4 to HTML5?

1. Reasons and goals for launch

To solve various problems existing on the web, the emergence of html5 is of great significance to the web.

a. The compatibility between web browsers is very low

Develop standardized html standards, analyze the functions of each web browser in detail, and use them as benchmarks in order to allow all major browsers to conform to a common standard.

b. The document structure is not clear enough

We used a lot of div elements before, and could not distinguish the text, function blocks, and introduced many semantic elements header, footer, nav Wait...

c. The functions of web applications are limited

Web applications are very different from apps. HTML5 also provides many APIs, and various browser manufacturers also Quickly encapsulate these APIs to make up for the limited functionality.

2. Syntax changes

a.docpyte declaration

HTML5 simplifies many subtle syntax, such as doctype declaration, you only need to write That's it.

HTML 4:

b. Specified character encoding

HTML 5 The method of specifying UTF-8 encoding is as follows

HTML 4:< ;meta http-equiv="content-type" content="text/html; charset=utf-8">

c. Attributes with boolean values

Values ​​can be omitted

d. Quotation marks can be omitted

Quotation marks can be omitted

There are many more details, so I won’t list them all here...

3. New tags and attributes

Add the attributes of the form

Add the attributes of a link

4. Abandoned tags and attributes

The abolition of the a link attribute.

The above is a brief introduction to the differences between HTML5 and HTML4. In fact, HTML5 has more features and advantages. We will summarize and share them with you later.

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