Bootstrap 4 徽章

.badge类是用来给内容添加额外信息的。例如，一些网站将通知的数量与链接相关联。当登录到一个特定的网站时，就会看到通知数量，它告诉人们通过点击它可以看到的新闻或通知的数量。
示例:

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Bootstrap Badges</title>
    <meta charset="utf-8">
    <meta name="viewport"
        content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href=
"https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
    <script src=
"https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js">
    </script>
    <script src=
"https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js">
    </script>
    <script src=
"https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js">
    </script>
</head>
<body>
    <h1 style="color:green;text-align:center;">
        GeeksforGeeks
    </h1>
    <div class="container">
        <h4>Notifications heading
            <span class="badge badge-secondary">
                4
              </span>
        </h4>
        <h4>Updates
            <span class="badge badge-secondary">
                2
              </span>
        </h4>
        <h4>Messages
            <span class="badge badge-secondary">
                1
              </span>
        </h4>
        <h4>Request
            <span class="badge badge-secondary">
                0
              </span>
        </h4>
    </div>
</body>
</html>

输出:

Bootstrap 4 徽章

情境徽章：情境类（.badge-*）用于改变徽章的颜色。徽章可以作为链接或按钮的一部分来提供一个计数器。根据他们的使用方式，徽章必须让用户感到困惑。为此，我们使用了不同的颜色变化，这样用户就不会感到困惑了。
示例:

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Bootstrap Badges</title>
    <meta charset="utf-8">
    <meta name="viewport"
        content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href=
"https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
    <script src=
"https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js">
    </script>
    <script src=
"https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js">
    </script>
    <script src=
"https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js">
    </script>
</head>
<body>
    <h1 style="color:green;text-align:center;">
        GeeksforGeeks
    </h1>
    <div class="container">
        <h4>Notifications heading
            <span class="badge badge-primary">
                4
              </span>
        </h4>
        <h4>Updates
            <span class="badge badge-warning">
                2
              </span>
        </h4>
        <h4>Messages
            <span class="badge badge-success">
                1
              </span>
        </h4>
        <h4>Request
            <span class="badge badge-danger">
                0
              </span>
        </h4>
    </div>
</body>
</html>

输出:

Bootstrap 4 徽章

柱状徽章： .badge-pill类用于使徽章的角更圆。
示例:

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Bootstrap Badges</title>
    <meta charset="utf-8">
    <meta name="viewport"
        content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href=
"https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
    <script src=
"https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js">
    </script>
    <script src=
"https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js">
    </script>
    <script src=
"https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js">
    </script>
</head>
<body>
    <h1 style="color:green;text-align:center;">
        GeeksforGeeks
    </h1>
    <div class="container">
        <h4>Notifications heading
            <span class="badge badge-primary badge-pill">
                4
              </span>
        </h4>
        <h4>Updates
            <span class="badge badge-warning badge-pill">
                2
              </span>
        </h4>
        <h4>Messages
            <span class="badge badge-success badge-pill">
                1
              </span>
        </h4>
        <h4>Request
            <span class="badge badge-danger badge-pill">
                0
              </span>
        </h4>
    </div>
</body>
</html>

输出:

Bootstrap 4 徽章

元素内的徽章：徽章可以在元素内创建。
示例:

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Bootstrap Badges</title>
    <meta charset="utf-8">
    <meta name="viewport"
        content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href=
"https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
    <script src=
"https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js">
    </script>
    <script src=
"https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js">
    </script>
    <script src=
"https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js">
    </script>
</head>
<body>
    <h1 style="color:green;text-align:center;">
        GeeksforGeeks
    </h1>
    <div class="container">
        <button type="button" class="btn btn-primary">
            <h4>Notifications heading
                <span class="badge badge-primary badge-danger">4</span>
            </h4>
        </button><br><br>
        <button type="button" class="btn btn-warning">
            <h4>Updates
                <span class="badge badge-light">2</span>
            </h4>
        </button><br><br>
        <button type="button" class="btn btn-primary">
            <h4>Messages
                <span class="badge badge-success">1</span>
            </h4>
        </button><br><br>
        <button type="button" class="btn btn-danger">
            <h4>Request
                <span class="badge badge-primary">0</span>
            </h4>
        </button>
    </div>
</body>
</html>

输出:

Bootstrap 4 徽章