Play rock, paper, scissors against PHP - Written to help educate a friend.

RockPaperScissors.php

<?php

// This gist was written for a high school student who told me about a project he was given to write
// a game of rock, paper, scissors. This gist was written to show him my solution to such a problem.

// Obviously, this is a PHP script to be run in the command line.
// Change the $myChoice variable to your choice as per the key below:

// 0 = Rock
// 1 = Paper
// 2 = Scissors

// Change this value to your selected option.
$myChoice = 0;

// The machine will randomly select an option (Note: PHP rand() will return a pseudo-random integer).
$machineChoice = rand(0, 2);

// Define an array of valid choices.
$validChoices = [0, 1, 2];

// Validate $myChoice against the valid choices.
if (in_array($myChoice, $validChoices)) {
    // The first level of the array is the machines choice. The array key relates to the key above.
    // The second level of the array is $myChoice. The array key also relates to the key above.
    // The resulting value, is a win/loss/draw value. Check the switch below.
    $matrix = [
        [2, 1, 0],
        [0, 2, 1],
        [1, 0, 2]
    ];
    $result = $matrix[$machineChoice][$myChoice];

    // check the result and print a result message.
    switch ($result) {
        case 2:
            echo "Draw.";
            break;
        case 1:
            echo "You Win.";
            break;
        case 0:
            echo "The Computer Wins.";
            break;
        default:
            echo "Something went wrong... Somehow.";
            break;
    }
} else {
    echo "Invalid Selection - Please choose 0 for Rock, 1 for Paper and 2 for Scissors.";
}

RockPaperScissorsCommand.php

<?php

namespace AppBundle\Command;

use Symfony\Bundle\FrameworkBundle\Command\ContainerAwareCommand;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;

/**
 * Rock, paper, scissors game written for a Symfony 3.0.9 command
 * 
 * Class RockPaperScissorsCommand
 * @package AppBundle\Command
 */
class RockPaperScissorsCommand extends ContainerAwareCommand
{
    /**
     * {@inheritdoc}
     */
    protected function configure()
    {
        $this
            ->setName('app:rock_paper_scissors_command')
            ->setDescription('A simple game of rock, paper, scissors.')
            ->addArgument('choice', InputArgument::REQUIRED, 'Rock, paper or scissors?');
    }

    /**
     * {@inheritdoc}
     */
    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $myChoice = $this->mapChoice($input->getArgument('choice'));
        $machineChoice = rand(0, 2);

        $validChoices = [0, 1, 2];

        if (in_array($myChoice, $validChoices)) {
            $matrix = [
                [2, 1, 0],
                [0, 2, 1],
                [1, 0, 2]
            ];
            $result = $matrix[$machineChoice][$myChoice];

            switch ($result) {
                case 2:
                    $result =  "Draw.";
                    break;
                case 1:
                    $result = "You Win.";
                    break;
                case 0:
                    $result = "The Computer Wins.";
                    break;
                default:
                    $result = "Something went wrong... Somehow.";
                    break;
            }

            // Tell the user who won
            $output->writeln('--- ' . $result . ' ---');
        }
    }

    /**
     * @param $choice
     * @return int|null
     */
    protected function mapChoice($choice){

        // Allow misspellings of the choices to convert to valid options.
        $rockChoices = ['r', 'rock', 'rok', 'roc'];
        $paperChoices = ['p', 'paper', 'papr', 'papre', 'parpe'];
        $scissorsChoices = ['s', 'scissors', 'scissor', 'scisors', 'sissors', 'sisors'];

        // Return an integer value to represent the choice
        if (in_array($choice, $rockChoices)) {
            return 0;
        } elseif (in_array($choice, $paperChoices)) {
            return 1;
        } elseif (in_array($choice, $scissorsChoices)) {
            return 2;
        } else {
            return null;
        }
    }
}