CSS中引号和非引号属性选择器之间的差异 [英] The difference between quoted and unquoted attribute selector in CSS

问题描述

我想知道css选择器中quoted和unquoted属性之间的区别是什么，对性能有什么影响。

  input [type =text] 
  

/

$ b b

 输入[type = text] 
  

$

解决方案

对于标识符，引号是可选的，但必须使用当它是字符串时。

作为字符串的常见示例包括：

• 包含空格（ ）




• 在数字后面加上连字符

使用数字开头（ 0-9 ul>



以下是标识符的完整规范：




在CSS中，标识符（包括选择器中的元素名称，类和ID）只有字符[a-zA-Z0-9]和ISO 10646字符U + 00A0和更高，加连字符（ - ）和下划线（_）;它们不能以数字，两个连字符或连字符后跟数字开头。标识符还可以包含转义字符和任何ISO 10646字符作为数字代码（见下一项）。例如，标识符B& W可以写成B \& W \？或B \26 W \3F。








---





a href =http://www.w3.org/TR/css3-selectors/#attribute-selectors =nofollow> http://www.w3.org/TR/css3-selectors/#attribute-选择器




I was wondering what is the difference between quoted and unquoted attributes in css selectors and does that have any effect on performance.

input[type="text"]

/

input[type=text]

Thanks in advance

解决方案

The above are the same. The quotes are optional for identifiers, but must be used when it is a string.

Some common examples of being a string include:

• Containing a space ()
• Beginning with a digit (0-9)
• Containing a hyphen after a digit

Here's the full spec of an identifier:

In CSS, identifiers (including element names, classes, and IDs in selectors) can contain only the characters [a-zA-Z0-9] and ISO 10646 characters U+00A0 and higher, plus the hyphen (-) and the underscore (_); they cannot start with a digit, two hyphens, or a hyphen followed by a digit. Identifiers can also contain escaped characters and any ISO 10646 character as a numeric code (see next item). For instance, the identifier "B&W?" may be written as "B\&W\?" or "B\26 W\3F".

---

Further reading: http://www.w3.org/TR/css3-selectors/#attribute-selectors

这篇关于CSS中引号和非引号属性选择器之间的差异的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！