html5 script,HTML 5 <script> Tag-优快云博客

HTML 5 Tag

Run

Stack editor

Unstack editor

The HTML tag is used for declaring a script (such as JavaScript) within your HTML document.

Also see the

tag for providing content to browsers that don't support your scripting language.

Attributes

HTML tags can contain one or more attributes. Attributes are added to a tag to provide the browser with more information about how the tag should appear or behave. Attributes consist of a name and a value separated by an equals (=) sign, with the value surrounded by double quotes. Here's an example, style="color:black;".

There are 3 kinds of attributes that you can add to your HTML tags: Element-specific, global, and event handler content attributes.

The attributes that you can add to this tag are listed below.

Element-Specific Attributes

The following table shows the attributes that are specific to this tag/element.

AttributeDescription

srcSpecifies a URI/URL of an external script.

asyncSpecifies whether a script will executed asynchronously, as soon as it is available.

This is a boolean attribute. If the attribute is present, its value must either be the empty string or a value that is an ASCII case-insensitive match for the attribute's canonical name, with no leading or trailing whitespace (i.e. either async or async="async").

Possible values:

[Empty string]

async

deferSpecifies whether the script is executed after the page has finished parsing, or immediately. If the async attribute is not present but the defer attribute is present, then the script is executed when the page has finished parsing. If neither attribute is present, then the script is fetched and executed immediately, before the user agent continues parsing the page.

Possible values:

[Empty string]

defer

typeSpecifies the scripting language as a content-type (MIME type).

charsetDefines the character encoding that the script uses.

crossoriginThis attribute is a CORS settings attribute. CORS stands for Cross-Origin Resource Sharing. The purpose of the crossorigin attribute is to allow you to configure the CORS requests for the element's fetched data. The values for the crossorigin attribute are enumerated.

Possible values:

ValueDescription

anonymousCross-origin CORS requests for the element will not have the credentials flag set. In other words, there will be no exchange of user credentials via cookies, client-side SSL certificates or HTTP authentication.

use-credentialsCross-origin CORS requests for the element will have the credentials flag set.

If this attribute is not specified, CORS is not used at all.

An invalid keyword and an empty string will be handled as the anonymous value.

Global Attributes

The following attributes are standard across all HTML 5 tags (although the tabindex attribute does not apply to dialog elements).

accesskey

autocapitalize

class

contenteditable

data-*

dir

draggable

hidden

inputmode

itemid

itemprop

itemref

itemscope

itemtype

lang

part

slot

spellcheck

style

tabindex

title

translate

For a full explanation of these attributes, see HTML 5 global attributes.

Event Handler Content Attributes

Event handler content attributes enable you to invoke a script from within your HTML. The script is invoked when a certain "event" occurs. Each event handler content attribute deals with a different event.

onabort

onauxclick

onblur

oncancel

oncanplay

oncanplaythrough

onchange

onclick

onclose

oncontextmenu

oncopy

oncuechange