问题
For example: <div/> instead of <div></div>.
I did this and apparently the HTML5 validator passed this as valid. I was wondering it this is actually true?
PS: I'm serving page as application/xhtml+xml
回答1:
This is not valid HTML 5 (HTML does not allow shorttags, the equivalent HTML construct is a single opening div tag). It is valid XHTML 5, as it is valid XML.
The reason why you might see this pass through a validator just fine is because of what you stated:
PS: I'm serving page as application/xhtml+xml
Which means that you tell the validator that it must treat your markup as XML. In other words your page is not HTML 5 at all.
回答2:
That syntax is allowed for a specific subset of HTML5 elements, known as void elements, and a few other cases:
Then, if the element is one of the void elements, or if the element is a foreign element, then there may be a single U+002F SOLIDUS character (/). This character has no effect on void elements, but on foreign elements it marks the start tag as self-closing.
Void elements:
area, base, br, col, command, embed, hr, img, input, keygen, link, meta, param, source, track, wbr
They're not allowed for any others, including <div>.
(I'd originally answered that yes, this is valid HTML5, since it's such a common construct in XML. Rex M, and a close reading of the spec, tells me that I'm wrong)
回答3:
No, technically using a self-closing <div/> tag is invalid HTML5. Using <div></div> works fine.
来源：https://stackoverflow.com/questions/3852469/is-it-valid-html5-to-use-a-single-tag-for-a-div