PHP纸牌游戏，比较高牌以获得赢家

我是PHP的新手，出于学习目的，我正在制作一个简单的纸牌游戏（我最终想把它变成二十一点），但现在我只想比较两个玩家的牌，看看谁的牌集最高，并以这种方式获得获胜者。我遇到了一个问题，当我显示php时，我得到一个空白屏幕，没有信息。*如果我删除"纸牌游戏.php"中的代码，那么我会得到两个玩家拥有的卡牌。在错误日志中，这也是显示错误的地方，但我无法弄清楚该段代码出了什么问题。那段代码中一定有什么东西阻止了它的工作......任何帮助将不胜感激。

我将发布以下四个文件：

卡.php

class Card
{
    private $suit;
    private $figure;

    public function __construct($Suit, $Fig) {
            $this->suit   = $Suit;
            $this->figure = $Fig;
    }
    public function __toString() {
            return $this->figure . ' of ' . $this->suit;
    }
    public function getFigure() {
            return $this->figure;
    }
    public function getCard() {
            echo $this->figure . " of " . $this->suit . ".<br />";
    }

}
?>

甲板.php

<?php //can't make objects out of abstract classes, but it's children can
abstract class Deck
{
protected $arrCards; 
protected $listOfCards;
/* abstract methods force classes that extends this class to implement them */
abstract public function dealCard(); //all classes that will inherit will inherit this method

/* already implemented methods */
public function __construct($Cards) {
    $this->arrCards = $Cards;
}
public function shuffleCards() {
    shuffle($this->arrCards);
}
public function listCards() {
    foreach($this->arrCards as $Card) {
        echo $Card . '<br />';
    }
}
}
 ?>

英语甲板.php

<?php
include_once "Deck.php"; 
include_once "Card.php"; 
class EnglishDeck extends Deck
{      
        //perhaps the keys?
    private $suits = array('Clubs', 'Diamonds', 'Hearts', 'Spades');
    private $cards = array(
    'Ace'=> 1, 
    2 => 2, 
    3 => 3, 
    4 => 4, 
    5 => 5, 
    6 => 6, 
    7 => 7, 
    8 => 8, 
    9 => 9, 
    10 => 10, 
    'Jack' => 10, 
    'Queen'=>10, 
    'King'=>10);
public function dealCard() {
    return array_pop($this->arrCards);
}
public function __construct() {
    $Cards = $this->initEnglishDeck();
    parent::__construct($Cards);
}
function initEnglishDeck() {
    $arrCards = array();
    foreach($this->suits as $Suit) {
        foreach ($this->cards as $Card) {
            $arrCards[] = new Card($Suit, $Card);
        }
    }
    return $arrCards;
}
}
$oBaraja = new EnglishDeck();
$oBaraja->shuffleCards();
?>

和纸牌游戏.php

   <?php
    include_once "Card.php";
   include_once "EnglishDeck.php";

$oBaraja = new EnglishDeck();
$oBaraja->shuffleCards();

//PLAYER 1
$oP1card1  = $oBaraja->dealCard();
echo("Player one has " . $oP1card1);
 $oP1card2  = $oBaraja->dealCard();
echo(" and a " . $oP1card2 );
$oPlayer1 = $oP1card1 + $oP1card2;
echo "<br>";
//PLAYER 2
$oP2card1  = $oBaraja->dealCard();
echo("Player two has " . $oP2card1);
$oP2card2  = $oBaraja->dealCard();
 echo(" and a " . $oP2card2);
 $oPlayer2 = $oP2card1 + $oP2card2;
 // THIS IS WHERE I AM GETTING ERRORS
 $oBaraja->compare($oPlayer1, $oPlayer2) {
    if($oPlayer1 > $oPlayer2){
        echo "Player 1 wins";
    } else if ($oPlayer1 < $oPlayer2) {
        echo "Player 2 wins";
    } else {
        echo "it's a tie";
    }
} 
?>