quick quiz

quick_quiz.php

<?php
1.
$x = true;
if ($x == 1 && $x==2 && $x==3){
    echo("ok");
}
2.

class Helm
{
    const DIRECTION_LEFT = 'left';
    const DIRECTION_RIGHT = 'right';
    const DIRECTION_CENTER = 'center';

    private $direction;
    private $angle = 0;
    /**
     * Checks possible angle values
     * 
     * @param  int    $angle in Celcius
     * @return bool
     */
    private function checkAngle(int $angle): bool
    {
        if ($angle > 100 || $angle < 0) {
            throw new \InvalidArgumentException("Invalid angle value");
        }
        return true;
    }
    /**
     * Turn direction to left
     * 
     * @param  int    $angle in Celcius
     * @return void
     */
    public function turnLeft(int $angle):void
    {
        $this->checkAngle($angle);
        $this->direction = self::DIRECTION_LEFT;
        $this->angle = $angle;
    }
    /**
     * Turn direction to right
     * 
     * @param  int    $angle in Celcius
     * @return void
     */
    public function turnRight(int $angle):void
    {
        $this->checkAngle($angle);
        $this->direction = self::DIRECTION_RIGHT;
        $this->angle = $angle;
    }
    /**
     * Set direction as center
     * Angle is 0
     * 
     * @return void
     */
    public function center():void
    {
        $this->direction = self::DIRECTION_CENTER;
        $this->angle = 0;
    }

    public function getDirection():string
    {
        return $this->direction;
    }

    public function getAngle():int
    {
        return $this->angle;
    }
}

class Bicycle
{
    private $wheels = [];
    private Helm $helm;
    private $speed = 0;

    public function __construct()
    {
        $this->helm = new Helm();
    }
    /**
     * Turn bicycle to left
     * 
     * @param  integer $angle in Celcius
     * @return void
     */
    public function turnLeft($angle = 90):void
    {
        $this->helm->turnLeft($angle);
    }
    /**
     * Turn bicycle to right
     * 
     * @param  integer $angle in Celcius
     * @return void
     */
    public function turnRight($angle = 90):void
    {
        $this->helm->turnRight($angle);
    }
    /**
     * Ride bicycle by center
     * 
     * @return void
     */
    public function center():void
    {
        $this->helm->center();
    }
    /**
     * Increase current speed
     * 
     * @param  int    $speed km\h
     * @return void
     */
    public function increaseSpeed(int $speed):void
    {
        $this->speed += $speed;
        if ($this->speed >= 60) {
            throw new \InvalidArgumentException("You can't ride that fast");
        }
    }
    /**
     * Decrease current speed
     * 
     * @param  int    $speed km\h
     * @return void
     */
    public function decreaseSpeed(int $speed):void
    {
        $this->speed -= $speed;
        if ($this->speed <= 0) {
            throw new \InvalidArgumentException("Speed can't be below 0");
        }
    }
    /**
     * Current speed
     * 
     * @return int
     */
    public function getCurrentSpeed():int
    {
        return $this->speed;
    }
}

3.

interface FileFinder
{
    public function getFiles();
}

class FinderByFilter implements FileFinder
{
/**
     * Current folder path
     * @var string
     */
    private $path;

    public function __construct(string $path)
    {
        $this->path = $path;
    }

    protected function getFilter(\RecursiveIteratorIterator $iterator): \IteratorIterator
    {
        return $iterator;
    }
    /**
     * Get all files in folder
     * @return generator object
     */
    public function getFiles():\Iterator
    {
        $dir = new \RecursiveDirectoryIterator($this->path);
        $iterator = new \RecursiveIteratorIterator($dir);
        $iterator = $this->getFilter($iterator);
        
        foreach ($iterator as $file) {
            yield $file;
        }

    }    
}
/**
 * Find jpeg files in folder
 */
class JpegFinder extends FinderByFilter
{
    /**
     * Regex expression
     * 
     * @var string
     */
    protected $mask;

    public function __construct(string $path)
    {
        parent::__construct($path);
        $this->mask = '/^.+\.(?:jpg|jpeg)/i';// any jpeg files
    }

    protected function getFilter(\RecursiveIteratorIterator $iterator): \IteratorIterator
    {
        $iterator = new \RegexIterator($iterator, $this->getMask(), \RecursiveRegexIterator::GET_MATCH);
        return $iterator;
    }
    /** Set mask for seaching */
    public function applyMask(string $mask)
    {
        $this->mask = $mask;
    }

    public function getMask(): string
    {
        return $this->mask;
    }
}

class PngConverter
{
    protected $format = 'png';
    /**
     * Convert image to png
     * 
     * @param  string $path [description]
     * @return string
     */
    public function convert(string $path): string
    {
        if (!file_exists($path)) {
            throw new \InvalidArgumentException("File does not exist");
        }
        $info = pathinfo($path);
        $newFile = sprintf("%s/%s.%s", $info['dirname'], $info['filename'], $this->format);

        // also it is possible to use command line for conversion
        $image = new \Imagick($path);
        $image->setImageFormat($this->format);
        
        $image->writeImage($newFile);
        return $newFile;
    }
}

$finder = new JpegFinder(".");
// $finder->applyMask('/some\.jpg/i');

$converter = new PngConverter();
foreach($finder->getFiles() as $file) {
    $converter->convert(array_pop($file));
}