Bootstrap中的帮助程序类包括pull-left，.pull-right，.center-block和其他类。
让我们看一个.clearfix类的例子-
要清除任何元素的浮点数，请使用.clearfix类-
<!DOCTYPE html> <html> <head> <title>Bootstrap Example</title> <link href = "/bootstrap/css/bootstrap.min.css" rel = "stylesheet"> <script src = "/scripts/jquery.min.js"></script> <script src = "/bootstrap/js/bootstrap.min.js"></script> </head> <body> <div class = "clearfix" style = "background: orange;border: 1px solid #000; padding: 10px;"> <div class = "pull-left" style = "background:#58D3F7;"> Quick Float to left </div> <div class = "pull-right" style = "background: #DA81F5;"> Quick Float to right </div> </div> </body> </html>