:where()

草案
本页尚未完工.

这是一个实验中的功能
此功能某些浏览器尚在开发中,请参考浏览器兼容性表格以得到在不同浏览器中适合使用的前缀。由于该功能对应的标准文档可能被重新修订,所以在未来版本的浏览器中该功能的语法和行为可能随之改变。

:where() CSS 伪类函数接受选择器列表作为它的参数,将会选择所有能被该选择器列表中任何一条规则选中的元素。

:where():is() 的不同之处在于,:where()优先级总是为 0 ,但是 :is() 的优先级是由它的选择器列表中优先级最高的选择器决定的。

语法

:where( <complex-selector-list> )

where
<complex-selector-list> = <complex-selector>#

where
<complex-selector> = <compound-selector> [ <combinator>? <compound-selector> ]*

where
<compound-selector> = [ <type-selector>? <subclass-selector>* [ <pseudo-element-selector> <pseudo-class-selector>* ]* ]!
<combinator> = '>' | '+' | '~' | [ '||' ]

where
<type-selector> = <wq-name> | <ns-prefix>? '*'
<subclass-selector> = <id-selector> | <class-selector> | <attribute-selector> | <pseudo-class-selector>
<pseudo-element-selector> = ':' <pseudo-class-selector>
<pseudo-class-selector> = ':' <ident-token> | ':' <function-token> <any-value> ')'

where
<wq-name> = <ns-prefix>? <ident-token>
<ns-prefix> = [ <ident-token> | '*' ]? |
<id-selector> = <hash-token>
<class-selector> = '.' <ident-token>
<attribute-selector> = '[' <wq-name> ']' | '[' <wq-name> <attr-matcher> [ <string-token> | <ident-token> ] <attr-modifier>? ']'

where
<attr-matcher> = [ '~' | | | '^' | '$' | '*' ]? '='
<attr-modifier> = i | s

规范

规范 状态 备注
Selectors Level 4
:where()
Working Draft Initial definition.

浏览器兼容性

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
:where()Chrome No support NoEdge No support NoFirefox Full support 78
Full support 78
Full support 77
Notes Disabled
Notes Enabled by default in Firefox Nightly.
Disabled From version 77: this feature is behind the layout.css.is-where-selectors.enabled preference (needs to be set to enabled). To change preferences in Firefox, visit about:config.
IE No support NoOpera No support NoSafari No support NoWebView Android No support NoChrome Android No support NoFirefox Android No support NoOpera Android No support NoSafari iOS No support NoSamsung Internet Android No support No

Legend

Full support  
Full support
No support  
No support
See implementation notes.
See implementation notes.
User must explicitly enable this feature.
User must explicitly enable this feature.

参见