Invalid class instantiation PHP-W1012
Bug risk
Critical
The class has been incorrectly instantiated, which would cause a runtime error.
This issue will be reported in the following cases:
- The constructor is supplied with more than or fewer parameters than it requires.
- The constructor is supplied with parameters of the wrong type.
- The constructor is not public.
- There is a typo in the class's name.
- Instantiated class is not found.
- You are attempting to instantiate an abstract class or interface. This is a forbidden operation.
This is not an exhaustive list of causes. Please refer to each occurrence's message for more details.
Bad practice
class Greet
{
public function __construct(string $message) {}
public function getInstance()
{
new self(); // invalid: "Greet" class's constructor invoked with 0 parameters, but 1 is required.
}
}
$greet = new Greet(1); // invalid: Greet expects its first parameter to be a string, but it is given an int.
interface Admin {}
$admin = new Admin(); // invalid: cannot instantiate an interface.
abstract class User
{
abstract public function getName();
}
$admin = new User(); // invalid: cannot instantiate an abstract class.
Recommended
class Greet
{
public function __construct(string $message) {}
public function getInstance()
{
new self('Hello');
}
}
$greet = new Greet('Hi');