php命名空间和动态语言特征

<?php
    class classname
    {
        function __construct()
        {
            echo __METHOD__,"
";
        }
    }
    function funcname()
    {
        echo __FUNCTION__,"
";
    }
    const constname = "global";
    $a = 'classname';
    $obj = new $a; // prints classname::__construct
    $b = 'funcname';
    $b(); // prints funcname
    echo constant('constname'), "
"; // prints global
?>

<?php
    namespace namespacename;
    class classname
    {
        function __construct()
        {
            echo __METHOD__,"
";
        }
    }
    function funcname()
    {
        echo __FUNCTION__,"
";
    }
    const constname = "namespaced";
    include 'example1.php';
    $a = 'classname';
    $obj = new $a; // prints classname::__construct
    $b = 'funcname';
    $b(); // prints funcname
    echo constant('constname'), "
"; // prints global
    /* 注意如果使用双引号, 一定要使用"\namespacename\classname"进行转义 */
    $a = '
amespacenameclassname';
    $obj = new $a; // prints namespacenameclassname::__construct
    $a = 'namespacenameclassname';
    $obj = new $a; // also prints namespacenameclassname::__construct
    $b = 'namespacenameuncname';
    $b(); // prints namespacenameuncname
    $b = '
amespacenameuncname';
    $b(); // also prints namespacenameuncname
    echo constant('
amespacenameconstname'), "
"; // prints namespaced
    echo constant('namespacenameconstname'), "
"; // also prints namespaced
?>