源代码：
左右布局
点击运行
<!DOCTYPE html> <html> <head> <title>Bootstrap 实例</title> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/css/bootstrap.min.css"> <script src="https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script> <script src="https://cdn.staticfile.org/popper.js/1.15.0/umd/popper.min.js"></script> <script src="https://cdn.staticfile.org/twitter-bootstrap/4.3.1/js/bootstrap.min.js"></script> </head> <body> <div class="container mt-3"> <h1>输入框大小</h1> <p>使用 .input-group-sm 类来设置小的输入框， .input-group-lg 类设置大的输入框：</p> <form> <div class="input-group mb-3 input-group-sm"> <div class="input-group-prepend"> <span class="input-group-text">Small</span> </div> <input type="text" class="form-control"> </div> </form> <form> <div class="input-group mb-3"> <div class="input-group-prepend"> <span class="input-group-text">Default</span> </div> <input type="text" class="form-control"> </div> </form> <form> <div class="input-group mb-3 input-group-lg"> <div class="input-group-prepend"> <span class="input-group-text">Large</span> </div> <input type="text" class="form-control"> </div> </form> </div> </body> </html>
运行结果