Brief Introduction to newly added and abolished attributes of html5

Comments: In HTML5, while adding and abolishing many elements, many attributes have also been added and abolished. For example, attributes related to forms/links have been added, and some attributes in HTML4 have been abolished. If you are interested, you can find out, it may be helpful for you to learn html5.

In HTML5, many attributes are added and abolished while many elements are added and abolished.

New attribute

1. Form-related attributes

Specify the autofocus attribute for input (type = text), select, textarea, And button. It enables the element to automatically obtain the focus when the screen is opened. Specify the placeholder attribute for input (type = text) and textarea. It will prompt the user's input, prompting the user to enter the content. Specify the form attribute for input, output, select, textarea, button, and fieldset. It declares the form to which it belongs, and places it in any position on the page without losing it. Specify the required attribute for input (type = text) and textarea. This attribute indicates that the user performs a check when submitting the request. Check that the input content must exist in the element. Add several new attributes for the input Tag: autocomplete, min, max, multiple, pattern, and step. You can also use the list attribute with the datalist element, and use the datalist element with the autocomplete attribute. The multiple Attribute allows multiple files to be uploaded at a time. The pattern attribute is used to verify the mode of the input field, which is actually a regular expression. The step attribute specifies the valid numeric interval of the input field (if step = "3", the valid numeric value should be-3, 0, 3, 6, and so on ), the step attribute can be used with the max and min attributes to create a valid value range. Add the formaction, formenctype, forpolichod, formnovalidate, and formtarget attributes to the input and button elements. You can reload the action, enctype, method, novalidate, and target attributes of the form element. Add the disabled attribute to the fieldset element. You can set its child element to the disabled state. Add the novalidate attribute to input, button, and form. You can cancel the related checks during submission, and the form can be submitted unconditionally.

2. Link-related attributes

Adds media attributes for a and area. Specify the reason why the target URL is optimized for media/devices. This attribute is used to specify that the target URL is designed for special devices (such as the iPhone), voice, or print media. This property can accept multiple values. It can only be used when the href attribute exists. Add the herflang and rel attributes for the area. HreflangAttribute specifies the language of the text in the linked document. This attribute can be used only when the href attribute is set. Note: This property is purely consulting. RelAttribute specifies the relationship between the current document and the linked document/resource. The rel attribute can be used only when the href attribute is used. Adds the size attribute to the link. The sizes attribute specifies the size of the linked resource. This attribute can be used only when the linked resource is an icon (rel = "icon. This property can accept multiple values. Values are separated by spaces. Add the target attribute to the base element to maintain consistency with the element.

3. Other attributes

Adds the reversed attribute to ol, which specifies the reverse display of the list. Add the charset attribute for meta to add the type and label attributes for the menu. Label defines the annotation of A Courseware for the menu. The type attribute enables the following menu, toolbar, and list cande to appear. Adds the scoped attribute to the style. It allows us to define styles for specified parts of the document, rather than the entire document. If the "scoped" attribute is used, the specified style can only be applied to the parent element and its child element of the style element. Adds or deletes a script Attribute. It defines whether the script is executed asynchronously. The async property only applies to external scripts (only when the src property is used). There are multiple ways to execute external scripts: If async = "async ": the script is executed asynchronously relative to the rest of the page (when the page continues parsing, the script will be executed) If async is not used and defer = "defer ": the script will be executed when parsing the page. If neither async nor defer is used, read and execute the script to add manifest to the html element before the browser continues parsing the page, when an offline web application is developed, it is used together with APIs to define a URL that describes the cached information of the document. Add attributes sandbox, seamless, and srcdoc to iframe. It is used to improve page security and prevent untrusted web pages from performing some operations.

Abolished attributes

Some attributes in HTML4 are no longer used in html5. they are replaced by other attributes or other methods.

Attributes used in HTML 4	Elements Using this attribute	Alternative solution in HTML 5
Rev	Link,	Rel
Charset	Link,	Use the HTTP Content-type Header element in the linked Resource
Shape, Coords	A	Use the area element to replace element
Longdesc	Img, iframe	Use element a to link to Principal description
Target	Link	Redundant attribute, omitted
Nohref	Area	Redundant attribute, omitted
Profile	Head	Redundant attribute, omitted
Version	Html	Redundant attribute, omitted
Name	Img	Id
Scheme	Meta	Use scheme only for a form field
Archive, Chlassid, codebose, codetype, declare, standby	Object	Use the data and typc attribute classes to call the plug-in. When you need to use these attributes to set parameters, use the param attribute.
Valuetype, Type	Param	The MIME type that is not declared using the name and value Attributes
Axis, Abbr	Td, th	Use a format that starts with a clear and concise text, followed by detailed text. You can use the title attribute for more details to make the content of a cell brief.
Scope	Td	Use the HTTP Content-type Header element in the linked Resource
Align	Caption, input, legend, div, h1, h2, h3, h4, h5, h6, p	Use CSS style sheets instead
Alink, Link, text, vlink, background, bgcolor	Body	Use CSS style sheets instead
Align, Bgcolor, border, cellpadding, cellspacing, frame, rules, width	Table	Use CSS style sheets instead
Align, Char, charoff, height, nowrap, valign	Tbody, thead, tfoot	Use CSS style sheets instead
Align, Bgcolor, char, charoff, height, nowrap, valign, width	Td, th	Use CSS style sheets instead
Align, Bgcolor, char, charoff, valign	Tr	Use CSS style sheets instead
Align, Char, charoff, valign, width	Col, colgroup	Use CSS style sheets instead
Align, Border, hspace, vspace	Object	Use CSS style sheets instead
Clear	Br	Use CSS style sheets instead
Compace, Type	Ol, ul, li	Use CSS style sheets instead
Compace	Dl	Use CSS style sheets instead
Compace	Menu	Use CSS style sheets instead
Width	Pre	Use CSS style sheets instead
Align, Hspace, vspace	Img	Use CSS style sheets instead
Align, Noshade, size, width	Hr	Use CSS style sheets instead
Align, Frameborder, scrolling, marginheight, marginwidth	Iframe	Use CSS style sheets instead
Autosubmit	Menu