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HomeWeb Front-endHTML TutorialCSS选择器的优先级_html/css_WEB-ITnose

分类:WEB前端时间: 2016年3月13日

在PHP程序员雷雪松的博客前面的文章已经详细的介绍了CSS选择器和CSS常用的属性和值。下面再讲解一下CSS选择器的优先级。 什么叫CSS选择器优先级呢?简单的讲就是浏览器通过CSS选择器组成的匹配规则判断定义的多条CSS指令优先级,决定最忠元素显示的属性值。那下面就具体的看看关于CSS选择器优先级的规则。

1、通过CSS选择器文件引入的方式。

(外部样式)External style sheet

2、CSSS选择器的优先权,

a. 内联样式表的权值最高1000

b. ID 选择器的权值为100

c. Class 类选择器或者属性选择符或者伪类的权值为10

d. HTML标签选择器或者伪元素选择符的权值为1

e.全局选择符*权值为0

3、!important 规则通常拥有最高级别的规则,同样的CSS选择优先级后面的覆盖前面,自定义的CSS样式优先级大于CSS继承的和浏览器默认CSS的优先级。

4、关于CSS选择器优先级的具体示例。

选择器 计算结果
* { } 0
p { } 1  (HTML标签选择器)
li:first-line { } 2  (HTML标签选择器,伪元素选择器)
div span { } 2  (2个HTML标签选择器)
ul ol+li { } 3  (3个HTML标签选择器)
h1 + *[rel=up] { } 11  (HTML标签选择器,属性选择器)
dl dt.red { } 13  (一个CLASS类选择器,3个HTML标签选择器)
h2.red.level { } 21  (两个CLASS类选择器,HTML标签选择器)
style=”” 10,0,0  (行内样式)
#page 100  (ID选择器)
body #main .left p { } 112  (两个HTML标签选择器,ID选择器, CLASS选择器类)
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