要在小，中，大和超大屏幕尺寸上对齐弹性项目，请使用justify-content-*-start类。
首先让我们看看小屏幕尺寸-
<div class="d-flex justify-content-sm-start bg-primary mb-5"> <div class="p-2 bg-info">Interface</div> <div class="p-2 bg-secondary">Packages</div> <div class="p-2 bg-warning">Multithreading</div> </div>
以相同的方式，将其实现为中等，大和超大屏幕尺寸，如下所示：
justify-content-md-start: Medium Screen size justify-content-lg-start: Large Screen size justify-content-xl-start: Extra Large Screen Size
您可以尝试运行以下代码以在不同屏幕尺寸的开头对齐弹性项目-
<!DOCTYPE html> <html lang="en"> <head> <title>Bootstrap Example</title> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/css/bootstrap.min.css"> <script src="https://cdn.staticfile.org/jquery/3.3.1/jquery.min.js"></script> <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/js/bootstrap.min.js"></script> </head> <body> <div class="container mt-3"> <h3>Java Topics</h3> <div class="d-flex justify-content-sm-start bg-primary mb-5"> <div class="p-2 bg-info">Interface</div> <div class="p-2 bg-secondary">Packages</div> <div class="p-2 bg-warning">Multithreading</div> </div> <div class="d-flex justify-content-md-start bg-primary mb-5"> <div class="p-2 bg-danger">Interface</div> <div class="p-2 bg-warning">Packages</div> <div class="p-2 bg-secondary">Multithreading</div> </div> <div class="d-flex justify-content-lg-start bg-primary mb-5"> <div class="p-2 bg-secondary">Interface</div> <div class="p-2 bg-info">Packages</div> <div class="p-2 bg-danger">Multithreading</div> </div> </div> </body> </html>