Base Browsers: IE8.0+, Firefox40.0+, Chrome40.0+, iOS8.0+, Android4.4+, Opera40.0+
E[att] { sRules }
例如：
<style>img[alt] {
margin: 10px;
}
</style>
<img src="https://www.cainiaoplay.com/manual/css3/selectors/attribute/%E5%9B%BE%E7%89%87url" alt="" />
<img src="https://www.cainiaoplay.com/manual/css3/selectors/attribute/%E5%9B%BE%E7%89%87url" /> 此例，将会命中第一张图片，因为匹配到了alt属性
| IE | Firefox | Chrome | Safari | Opera | iOS Safari | Android Browser | Android Chrome |
|---|---|---|---|---|---|---|---|
| 6.0 | 2.0+ | 4.0+ | 3.1+ | 3.5+ | 3.2+ | 2.1+ | 18.0+ |
| 7.0+ |