类的方括号选择器 [英] Square brackets selector for classes

问题描述

我找到了示例的响应式电子邮件模板，其中有诸如以下CSS声明之类的CSS声明：

I have found an example of responsive email templates where there are such CSS declarations such as the following:

a[class="btn"]

为什么使用这种语法，如果它完全相同：

Why is this syntax used if it's totally the same as:

a.btn

是否对移动浏览器或其他任何内容有影响？

Does it have any impact on mobile browsers or anything else?

推荐答案

[] 语法是属性选择器。

a[class="btn"]

这将选择< a> 标记与 class =btn。但是，不会选择 class =btn btn_red的< a> >，例如（而 a.btn 会）。

This will select any <a> tag with class="btn". However, it will not select <a> which has class="btn btn_red", for example (whereas a.btn would). It only exactly matches that attribute.

您可能想要阅读你必须记住的30个CSS选择器。这对任何即将到来的网络开发者来说都是无价的。

You may want to read The 30 CSS Selectors you Must Memorize. It's invaluable to any up-and-coming web developer.

这篇关于类的方括号选择器的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！