// 假设URL是 http://example.com/page.php?name=John&age=30
$name = $_GET['name']; // 获取name参数的值 "John"
$age = $_GET['age'];   // 获取age参数的值 "30"

// 安全起见，应该先检查参数是否存在
if (isset($_GET['name'])) {
    $name = $_GET['name'];
} else {
    $name = '默认值';
}

$name = filter_input(INPUT_GET, 'name', FILTER_SANITIZE_STRING);
$age = filter_input(INPUT_GET, 'age', FILTER_SANITIZE_NUMBER_INT);

$queryString = $_SERVER['QUERY_STRING']; // 获取"name=John&age=30"

// 获取并解析所有GET参数
$params = $_GET;

// 遍历所有参数
foreach ($params as $key => $value) {
    echo "参数名: $key, 值: $value <br>";
}

// 安全获取参数的示例
$name = isset($_GET['name']) ? htmlspecialchars($_GET['name']) : '默认名';
$age = isset($_GET['age']) ? intval($_GET['age']) : 0;

$param = isset($_GET['param']) ? $_GET['param'] : 'default';

$encodedValue = urlencode('特殊&字符');
$decodedValue = urldecode($_GET['param']);

if (isset($_GET['colors']) && is_array($_GET['colors'])) {
    foreach ($_GET['colors'] as $color) {
        echo htmlspecialchars($color) . "<br>";
    }
}

$currentUrl = "http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";