css - CSS中带引号和不带引号的属性选择器的区别

Question

我想知道 css 选择器中带引号和不带引号的属性有什么区别，这对性能有什么影响。

input[type="text"]

/

input[type=text]

提前致谢

Answer 1

以上相同。 identifiers 的引号是可选的, 但当它是 string 时必须使用.

成为 string 的一些常见示例包括:

• 包含一个空格()
• 以数字开头 (0-9)
• 在数字后包含一个连字符

这是 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".

---

进一步阅读:http://www.w3.org/TR/css3-selectors/#attribute-selectors