php开发中如何获取所在全局变量的代码实例

php开发中如何获取所在全局变量的代码实例  

$globals --- 保存所有全局变量(只在当前页面中的) get_defined_vars() --- 返回由所有已定义变量所组成的数组(包括全局变量,超全局变量等) get_defined_constants() --- 返回由所有已定义常量所组成的数组

    function cleanglobal($global_array, $arg, $specialchars = true, $default = null) {
    if(key_exists($arg, $global_array) && $global_array[$arg] != null && $global_array[$arg] != "") {
    if($specialchars) {
    return htmlspecialchars($global_array[$arg]);//www.3ppt.com
    } else {
    return $global_array[$arg];
    }
    } else {
    return $default;
    }
    }


table of contents
superglobals — superglobals are built-in variables that are always available in all scopes
$globals — references all variables available in global scope
$_server — server and execution environment information
$_get — http get variables
$_post — http post variables
$_files — http file upload variables
$_request — http request variables
$_session — session variables
$_env — environment variables
$_cookie — http cookies
$php教程_errormsg — the previous error message
$http_raw_post_data — raw post data
$http_response_header — http response headers
$argc — the number of arguments passed to script
$argv — array of arguments passed to script