復制代碼 代碼如下:

<?php
echo '<pre>';
$b = array(1,1,2,3,5,8);
$arr = get_defined_vars();
// 打印 $b
print_r($arr["b"]);
// 打印所有服務器變量
print_r($arr["_SERVER"]);
// 打印變量數組的所有可用鍵值
print_r(array_keys(get_defined_vars()));
?>
2. get_defined_functions (PHP 4 >= 4.0.4, PHP 5) — 獲取所有已經定義的函數
array get_defined_functions ( void ) //void 表示為空，不需要任何參數
<?php
echo '<pre>';
function foo()
{
    echo "This is my function foo";
}
$arr = get_defined_functions();
print_r($arr);
?>

復制代碼 代碼如下:

<?php
echo '<pre>';
print_r(get_loaded_extensions());
?>

復制代碼 代碼如下:

<?php
echo '<pre>';
print_r(get_extension_funcs("gd"));
print_r(get_extension_funcs("xml"));
?>

復制代碼 代碼如下:

<?php
echo '<pre>';
define("MY_CONSTANT", 1);
print_r(get_defined_constants(true));
?>

復制代碼 代碼如下:

<?php
echo '<pre>';
//define classone
class classone { }
//define classtwo
class classtwo { }
//This will show X classes (built-ins, extensions etc) with
//classone and classtwo as the last two elements
print_r(get_declared_classes());
//define classthree
class classthree { }
//...and four
class classfour { }
//Shows the same result as before with class three and four appended
print_r(get_declared_classes());
?>