- var_dump: documentation ( source)
<?php
$rc = new ReflectionClass('DateTime');
$rps = $rc->getMethod('__construct')->getParameters();
foreach ($rps as $rp) {
echo ' $'.$rp->getName()."\n";
echo '$rp->isOptional()'."\n";
var_dump($rp->isOptional());
echo '$rp->isDefaultValueAvailable()'."\n";
var_dump($rp->isDefaultValueAvailable());
echo "\n\n";
}