- var_dump: documentation ( source)
<?php
foreach ((new ReflectionClass('\DateTime'))->getMethods() as $method) {
if ($method->getName() == 'modify') {
$returnType = $method->getTentativeReturnType();
if ($returnType instanceof ReflectionUnionType) {
foreach ($returnType->getTypes() as $type) {
var_dump($type->getName());
}
}
}
}