Introduction to the six attributes in the <script> tag-JS Tutorial-php.cn

This article brings you an introduction to the six attributes in the tag. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

Attribute 1: async

Optional async is a newly added attribute of html5. Officially, it means that the script should be downloaded immediately, but It does not hinder other operations on the page. In simple terms, js is loaded and executed asynchronously. It is asynchronous with the rendering of dom. Async is only valid for external script files.

Attribute two: charset

Optional represents the code and character set specified through the src attribute. It is stipulated that in external script files, if the character encoding in the external file is different from the encoding in the main file, the charset attribute must be used.

Attribute three: defer

Optional indicates that the script can be delayed until the document is completely parsed and displayed before execution. It is only valid for external files. Popular That is to say, the js file is loaded together with the dom structure, but the js file will wait until the html is rendered before executing.

Attribute 4: language

Obsolete Originally used to indicate the scripting language (JavaScript...) used by code editors, most browsers will ignore it This attribute is therefore not necessary.

Attribute five: src

Optional Indicates the external file containing the code to be executed

Attribute five: type

Optional The type attribute specifies the MIME type of the script. In HTML5, the type attribute is no longer required. The default value is "text/javascript".