jquery实现折叠菜单

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>jQuery 折叠菜单</title>
    <style>
        .menu-item {
            cursor: pointer;
        }
        .sub-menu {
            display: none;
        }
    </style>
    <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
</head>
<body>
    <div class="menu">
        <div class="menu-item">菜单1
            <div class="sub-menu">
                <div>子菜单1-1</div>
                <div>子菜单1-2</div>
            </div>
        </div>
        <div class="menu-item">菜单2
            <div class="sub-menu">
                <div>子菜单2-1</div>
                <div>子菜单2-2</div>
            </div>
        </div>
    </div>

    <script>
        $(document).ready(function() {
            $('.menu-item').click(function() {
                $(this).find('.sub-menu').slideToggle();
            });
        });
    </script>
</body>
</html>

$('.menu-item').click(function(event) {
    event.preventDefault();
    $(this).find('.sub-menu').slideToggle();
});