通过将前置和附加内容添加到输入字段，可以将公共元素添加到用户的输入中。例如，您可以添加美元符号，@作为Twitter用户名或其他任何可能对于您的应用程序界面通用的符号。
您可以尝试运行以下代码来创建Bootstrap输入组
<!DOCTYPE html> <html> <head> <title>Bootstrap Input Group</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 style = "padding: 100px 100px 10px;"> <form class = "bs-example bs-example-form" role = "form"> <div class = "input-group"> <span class = "input-group-addon">@</span> <input type = "text" class = "form-control" placeholder = "twitterhandle"> </div> <br> <div class = "input-group"> <input type = "text" class = "form-control"> <span class = "input-group-addon">.00</span> </div> <br> <div class = "input-group"> span class = "input-group-addon">$</span> <input type = "text" class =" form-control"> <span class = "input-group-addon">.00</span> </div> </form> </div> </body> </html>