Strategy Pattern Educational Code

strategy_pattern_tutorial.php

<?php

interface RESTAuthDriver
{
    public function setApiClient(RESTSpeaker $apiClient);
    public function generateGuzzleAuthOptions(): array;
}

interface Foo2
{
    public function hi();
}

abstract class Foo
{
//    public function hi() { echo "Hi\n"; }
    abstract protected function hi();

    public function greet()
    {
        echo $this->hi();
    }
}

$realFoo = new class extends Foo
{
    protected function hi()
    {
        echo "Foo\n";
    }
};

class Bar extends Foo
{
    protected function hi()
    {
        echo "Bar\n";
    }
}

$hiStrategy = 'BarZ';
(new $hiStrategy)->greet();

$realFoo->greet();
(new Bar())->greet();