Nullable return types in PHP7
PHP 7.1 Now supports nullable return types. The first RFC I linked to is the one they went for:
function nullOrString(int $foo) : ?string
{
return $foo%2 ? "odd" : null;
}
old answer:
Since my comment was actually an answer to the question:
PHP 7 won't support nullable return-types just yet, but there's an RFC out to address just that, it aims to land in PHP 7.1. If it passes, the syntax would then affect all type-hints (both return types and type-hints):
public function returnStringOrNull(?array $optionalArray) : ?string
{
if ($optionalArray) {
return implode(', ', $optionalArray);//string returned here
}
return null;
}
There's also a competing RFC to add union types, which would be able to do the same thing, but would look different:
public function returnStringOrNull(array|null $optionalArray) : string|null
{
if ($optionalArray) {
return implode(', ', $optionalArray);//string returned here
}
return null;
}
For now, though, you'll have to write:
public function returnStringOrNull( array $optionalArray = null)
{
if ($optionalArray) {
return implode(', ', $optionalArray);
}
}
Or just return an empty string to be consistent with the return type, and check falsy value:
public function returnStringOrNull( array $optionalArray = null) : string
{
if ($optionalArray) {
return implode(', ', $optionalArray);
}
return '';
}
//call
$string = $x->returnStringOrNull();
if (!$string) {
$string = $x->returnStringOrNull(range(1, 10));
}
Nullable Types are available in PHP 7.1.
This is a syntax example:
public function getName(): ?string
{
return $this->name; // name can be null
}
PHP 7.1 is now GA and you can upgrade from PHP 7.0 (there are only few backward incompatible changes that you have to check)