You just add this code
$clasa = (object) array(
'e1' => array('nume' => 'Nitu', 'prenume' => 'Andrei', 'sex' => 'm', 'varsta' => 23),
'e2' => array('nume' => 'Nae', 'prenume' => 'Ionel', 'sex' => 'm', 'varsta' => 27),
'e3' => array('nume' => 'Noman', 'prenume' => 'Alice', 'sex' => 'f', 'varsta' => 22),
'e4' => array('nume' => 'Geangos', 'prenume' => 'Bogdan', 'sex' => 'm', 'varsta' => 23),
'e5' => array('nume' => 'Vasile', 'prenume' => 'Mihai', 'sex' => 'm', 'varsta' => 25)
);
If you want to see is this stdClass object just call this
print_r($clasa);
If you want to convert an array to object code will be
$arr = array('a'=>'apple','b'=>'ball');
$arr = (object) $arr;
You don't need to use stdClass. It will automatically converted to stdClass