Why Does My PHP Child Class Method Get a 'Strict Standards' Error When Inheriting?

Compatibility of Method Declarations in PHP

When inheriting methods from a parent class, it's essential to ensure that the declarations in the child class are compatible with the parent method. The error message, "Strict Standards: Declaration of childClass::customMethod() should be compatible with that of parentClass::customMethod()", indicates that there's a mismatch between the method signatures in the parent and child classes.

Possible Causes of the Error:

The following are common reasons for this error:

• Differing Arguments: The child method has a different number or type of arguments than the parent method.
• Changed Access Level: The child method has a different access level (e.g., public, private, protected) than the parent method.

Ensuring Compatibility:

To resolve the error, you must ensure that the child method declaration is compatible with the parent method in the following ways:

• Match Arguments: The child method must have the same number and type of arguments as the parent method.
• Maintain Access Level: The child method must have the same or stricter access level than the parent method.

Additional Information:

Documentation on method compatibility in PHP can be found in the following sources:

• [PHP Manual: Method Overriding](https://www.php.net/manual/en/language.oop5.overriding.php)
• [PHP Inheritance](https://www.tutorialrepublic.com/php-tutorial/php-inheritance.php)

By verifying the compatibility of method declarations, you can avoid the "Strict Standards" error and ensure proper inheritance and method overriding in your PHP code.

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