Question

我的numberOfDecks方法遇到问题。我尝试调用在我的构造函数中创建的卡片数组，但是一个错误不断出现，我传递了一个未定义的变量（$ cards）。我认为因为它是一个全局变量，所以$ cards可以被调用到numberOfDecks方法。

<?php
/* creating a deck of cards class to be used in a blackJack game*/

class Deck{

  public  $cards = array();

  //creates an instance of a deck of cards (works)

  public function __construct(){
    $values =array('2','3','4','5','6','7','8','9','10','J','Q','K','A');
    $suits =array('Diamond','Club','Heart','Spade');
      foreach ($suits as $suit) {
         foreach($values as $value){
           $this->cards[] = "$value of $suit's";
         }
      }
  }

  /*trying to add more decks to increase number of total cards
  in my array  (does not work)*/

  public function numberOfDecks($number){

    $this->cards = $cards;
    $this->number= $number;
    for($i = 0 ; $i < $number; $i++){
          array_push($cards[],$i);
    }
    return $cards;

  }
}



$deck = new Deck();//works as expected
$deck->numberOfDecks(3);//trouble 
$shuffled = shuffle($deck->cards);//works as expected
var_dump($deck);

Answer 1

您的变量$cards未定义，因为您没有声明它。

public function numberOfDecks($number){

$this->cards = $cards;

你可能想要翻转分配方向。

$cards = $this->cards;

鉴于您对在对象总牌中添加套牌的评论，在翻转分配方向后，请尝试使用array_merge

Here's a working fiddle.

<?php

class Deck{

  public  $cards = array();

  //creates an instance of a deck of cards (works)

  public function __construct(){
    $values =array('2','3','4','5','6','7','8','9','10','J','Q','K','A');
    $suits =array('Diamond','Club','Heart','Spade');
      foreach ($suits as $suit) {
         foreach($values as $value){
           $this->cards[] = "$value of $suit's";
         }
      }
  }

    public function numberOfDecks($number){

        $cards = $this->cards;

        $this->number = $number;
        for($i = 0 ; $i < $number; $i++){
            $this->cards = array_merge($this->cards, $cards);
        }

    }
}



$deck = new Deck();//works as expected

// how many cards are intially constructed?
echo "count of cards in new deck: " . count($deck->cards) . "\n<br/>\n";

// add 3 more decks of cards
$deck->numberOfDecks(3);//trouble 
echo "count of cards after adding 3 decks: " . count($deck->cards);

// $shuffled = shuffle($deck->cards);//works as expected
// var_dump($deck);

此输出结果：

新牌组中的牌数：52
  添加3个套牌后的卡数：208

无法理解在类中调用全局变量到类

1 个答案: