dependency-injection-as-a-tool-for-testing-a-unit.php

<?php

class Foo
{
    public function doSomething($id, $name, $email)
    {
        $bar = new Bar;

        // .. possibly manipulate $id, $name and $email

        // assume we want to edit a row in a database and
        // then return an array of data containing that row
        return $bar->editAndReturnUser($id);
    }
}