Does php 7 support type hinting for class properties?
I mean, not just for setters/getters but for the property itself.
Something like:
class Foo {
/**
*
* @var Bar
*/
public $bar : Bar;
}
$fooInstance = new Foo();
$fooInstance->bar = new NotBar(); //Error
PHP 7.4 will support typed properties like so:
class Person
{
public string $name;
public DateTimeImmutable $dateOfBirth;
}
PHP 7.3 and earlier do not support this, but there are some alternatives.
You can make a private property which is accessible only through getters and setters which have type declarations:
class Person
{
private $name;
public function getName(): string {
return $this->name;
}
public function setName(string $newName) {
$this->name = $newName;
}
}
You can also make a public property and use a docblock to provide type information to people reading the code and using an IDE, but this provides no runtime type-checking:
class Person
{
/**
* @var string
*/
public $name;
}
And indeed, you can combine getters and setters and a docblock.
If you're more adventurous, you could make a fake property with the __get
, __set
, __isset
and __unset
magic methods, and check the types yourself. I'm not sure if I'd recommend it, though.