Book-page-184

<?php

interface a{
    public function a1();
}

interface b{
    public function b1();
}

interface x extends a, b {
    public function x1();
}

class SomeClass implements x {
    public function a1(){ //method from interface a
        echo "SomeClass::a1()<br>";
    }

    public function b1(){ //method from interface b
        echo "SomeClass::b1()<br>";
    }

    public function x1(){ //method from interface b
        echo "SomeClass::x1()<br>";
    }
}

$o = new SomeClass();
$o->a1();
$o->b1();
$o->x1();

?>