Warning example

borg.php

<?php 

class Person
{
    function assimilate($alwaysAskPermission = true)
    {
        // code
    }
}

class Borg extends Person
{
    function assimilate()
    {
        // we are the borg, resistance is futile
    }
}

// outputs a warning: Strict standards: Declaration of Borg::assimilate() should be compatible with Person::assimilate($alwaysAskPermission = true)