:empty
:empty
该:empty伪类代表没有子节点的所有元素。这里只考虑元素节点和文本（包括空格）。注释或处理指令不影响元素是否被认为是空的。
/* Selects any <div> that contains no content */
div:empty {
background: lime;
}
语法
:empty
实例
body {
display: flex;
justify-content: space-around;
}
.box {
background: red;
height: 100px;
width: 100px;
}
.box:empty {
background: lime;
}
<div class="box"><!-- I will be lime --></div>
<div class="box">I will be red</div>
<div class="box">
<!-- I will be red because of the whitespace around this comment -->
</div>
规范
| Specification | Status | Comment |
|---|---|---|
| Selectors Level 4The definition of ':empty' in that specification. | Working Draft | No change |
| Selectors Level 3The definition of ':empty' in that specification. | Recommendation | Initial definition |
浏览器兼容性
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic support | 1.0 | (Yes) | 1.0 (1.7 or earlier) | 9.0 | 9.5 | 3.1 |
| Feature | Android | Edge | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support | 2.1 | (Yes) | 1.0 (1) | 9.5 | 10.0 | 3.1 |
