* CSS操作符是什么？有没有其他的CSS操作符？ [英] What does the * CSS operator do? Are there any other CSS operators?

问题描述

在学习如何从CSS中的列表元素构建嵌套表时，我偶然发现了这个页面： http://css.maxdesign.com.au/listamatic2/horizo​​ntal01.htm 。

我注意到样式表使用了几个符号，在CSS中不熟悉，即> 和 * 符号，似乎是某种类型的CSS运算符。

例如：

  ul #navlist li * a：link，ul＃navlist li * a：visited 
  

并且发现> 只是表示两个元素之间的父/子关系，但我仍然不知道 * 。我也很想知道是否还有其他的操作符，如果是这样，可以有人指示我参考所有这些？

解决方案

* 是通用选择器。它选择任何元素。

但是，它是一个简单选择器，因此它不属于与所谓的组合器（表示两个元素之间的关系）。 > 是子组合器，如你所说的定义两个元素之间的父子关系。

ul＃navlist 和 li ， li code> * 等都是后代组合器。与> 不同，该空格并不表示父子关系;它只是要求一个元素包含在某处，无论是一个孩子，孙子，孙子等，但不是兄弟姐妹。

/ em>这两个选择器之间（从你的链接）：

  ul＃navlist li& a：link，ul＃navlist li> a：visited 
 ul＃navlist li * a：link，ul＃navlist li * a：visited 
  

是第一个使用> 要求 a：link 和 a ：直接位于 ul＃navlist li 元素中的元素

，而第二个与 * 要求 a：link 和 a ：<@ code>元素

位于 ul＃navlist li 内的任何元素内。

换句话说， a：link，a：visited 是不能直接 li 。

While studying how to build a nested table from list elements in CSS, I stumbled across this page: http://css.maxdesign.com.au/listamatic2/horizontal01.htm.

I noticed that the stylesheet uses a few symbols I'm not familiar with in CSS, namely the > and * symbols as what seem to be some kind of CSS operators.

For example:

ul#navlist li * a:link, ul#navlist li * a:visited

I was able to Google and find out that > simply indicates a parent/child relationship between two elements, but I still have no idea what * does. I'm also curious to know whether or not there are other "operators" like these, and if so, could somebody direct me to a reference of all of them?

解决方案

* is the universal selector. It selects any element.

However, it's a simple selector, and as such it doesn't belong in the same family as what are called combinators (which indicate relationships between two elements). > is the child combinator, which as you say defines a parent-child relationship between two elements.

The spaces between ul#navlist and li, li and *, etc are all descendant combinators. Unlike >, the space doesn't indicate a parent-child relationship; it just asks for an element that's contained somewhere within, whether it's a child, grandchild, great-grandchild, etc, but not a sibling.

The difference between these two selectors (from your link):

ul#navlist li > a:link, ul#navlist li > a:visited
ul#navlist li * a:link, ul#navlist li * a:visited

Is that the first one with > asks for a:link and a:visited elements
that sit directly within ul#navlist li elements,

while the second one with * asks for a:link and a:visited elements
that sit within any element that's within ul#navlist li.
In other words, a:link, a:visited that's not directly within ul#navlist li.

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