在学习bootstrap中的下拉菜单时，遇到下面情况：
<div class="dropdown"> <button class="btn btn-default dropdown-toggle" type="button" id="dropdownMenu1" data-toggle="dropdown"> 下拉菜单 <span class="caret"></span> </button> <ul class="dropdown-menu pull-right" role="menu" aria-labelledby="dropdownMenu1"> … </ul></div>
添加ul的类名为pull-right或dropdown-menu-right，可以改变下拉菜单的对其方向，效果图为：
默认样式为:
下面贴上：.pull-right的css代码
.dropdown-menu.pull-right { right: 0; left: auto;}.dropdown-menu-right { right: 0; left: auto;}但还需要设置父元素div的样式为float:left！！！
原因：
div是块级元素，会自动填满父元素的宽度，效果图：
当设置了div的float为left之后，div会脱离文档流，从而包裹button元素，是菜单向button右边对齐
假如你有补充，请评论下。么么哒~~~
What are the international mailboxes?
How to extract audio from video in java
Detailed process of upgrading win7 system to win10 system
host file
Windows photos cannot be displayed
python absolute value
How to calculate the factorial of a number in python
Solution to the problem that setting the Chinese interface of vscode does not take effect
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
