trait

<?php

trait hello{
    public function say_hello(){
        echo "Hello world";
    }
}

trait bye{
    public function say_bye(){
        echo "Bye everyone";
    }
}

class base{
    use hello;
    use bye;
}

class base2{
    use hello;
}

$obj = new base();
$obj2 = new base();

$obj->say_hello();
echo "<br>";
$obj->say_bye();
echo "<br>";
$obj2->say_hello();

?>