bootstrap html coding specification_html/css_WEB-ITnose

1.1. Syntax

1. Use two spaces instead of tabs - this is the only way to ensure consistent presentation in all environments.

2. Nested elements should be indented once (i.e. two spaces).

3. For attribute definitions, make sure to use double quotes and never single quotes.

4. Do not add a slash at the end of a self-closing element - the HTML5 specification clearly states that this is optional.

5. Do not omit optional closing tags (for example, or ).

Hello, world!

1.2 . HTML5 doctype

adds a standard mode declaration to the first line of each HTML page to ensure consistent presentation in each browser.

< ;/html>

1.3. Language attribute

According to the HTML5 specification:

It is strongly recommended to specify the lang attribute for the html root element to set the correct language for the document. This will help speech synthesis tools determine the pronunciation they should use, help translation tools determine the rules they should follow when translating, and so on.

1.4. IE Compatibility Mode

IE supports specific tags to determine the IE version that should be used to draw the current page. Unless there are strong special needs, it is best to set it to edge mode to notify IE to adopt the latest mode it supports.

1.5. Character encoding

By explicitly declaring the character encoding, This ensures that the browser can quickly and easily determine how the page content should be rendered. The advantage of this is that you can avoid using character entities in HTML, so that everything is consistent with the document encoding (usually UTF-8 encoding).

1.6. Introducing CSS and JavaScript File

According to the HTML5 specification, there is generally no need to specify the type attribute when introducing CSS and JavaScript files, because text/css and text/javascript are their default values ​​respectively.

1.7. Practicality is king

Try to follow HTML standards and semantics, but don’t sacrifice practicality. Try to use the fewest tags and keep complexity to a minimum at all times.

1.8. Attribute order

HTML attributes should be arranged in the order given below to ensure the readability of the code.

class

id, name

data-*

src, for, type, href

title, alt

aria-*, role

class is used to identify highly reusable components, so it should be ranked first. The id is used to identify a specific component and should be used with caution (for example, bookmarks within a page), so it comes second.

Example link

1.9. Boolean attributes

Boolean attributes can be declared without assigning a value. The XHTML specification requires it to be assigned a value, but the HTML5 specification does not.

If the Boolean attribute of the element has a value, it is true; if it has no value, it is false.

If the attribute exists, its value must be an empty string or [...] the canonical name of the attribute, and do not add trailing whitespace.

To put it simply, there is no need to assign a value.

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1.10. Reduce Number of tags

When writing HTML code, try to avoid redundant parent elements. Many times, this requires iteration and refactoring to achieve. Please look at the following case:

1.11. Tags generated by JavaScript

Tags generated by JavaScript make content difficult to find and edit, and reduce performance. Avoid it when you can.