php variable variables problem

Question

$_POST[\'asdf\'] = \'something\';

function test() {
    // NULL -- not what initially expected
    $string = \'_POST\';
    echo \'====\';
    var_dump(${$string});         


        

Answer 1

Look at here

Please note that variable variables cannot be used with PHP's Superglobal arrays within functions or class methods. The variable $this is also a special variable that cannot be referenced dynamically.