dynamic access constant - fork | making more promising and fail-safe

constantAccess.php

<?php

/* fork: making more promising and fail-safe */

class RegionVO {
    const NSW = 35;
    const ACT = 37;
    const VIC = 38;
    const QLD = 9;
    const SA = 36;
    const WA = 39;
    const NT = 40;
    const TAS = 26;
    
    public function getID($alias) {
        $refl = new ReflectionClass($this);
        return $refl->getConstant(strtoupper($alias));
    }
}

class RegionVO1 extends RegionVO {
    const VIC = 48;
    const NIU = 58;
}
 
$rvo = new RegionVO();
echo $rvo->getID('vic').PHP_EOL; // original

$rvo1 = new RegionVO1();
echo $rvo1->getID('vic').PHP_EOL; // overwritten
echo $rvo1->getID('nt').PHP_EOL; // inherited
echo $rvo1->getID('niu').PHP_EOL; // new constant
echo $rvo1->getId('abc'); // non-existent => false