php -正确格式化链接

function formatUrl($protocol, $host, $path = '', $query = [], $fragment = '') {
    $url = $protocol . '://' . $host;
    if (!empty($path)) {
        $url .= '/' . ltrim($path, '/');
    }
    if (!empty($query)) {
        $url .= '?' . http_build_query($query);
    }
    if (!empty($fragment)) {
        $url .= '#' . $fragment;
    }
    return $url;
}

// 示例用法
$protocol = 'https';
$host = 'www.example.com';
$path = 'path/to/resource';
$query = ['key' => 'value'];
$fragment = 'section1';

echo formatUrl($protocol, $host, $path, $query, $fragment);
// 输出: https://www.example.com/path/to/resource?key=value#section1