Java：我如何製作一個數組並在構造函數中用對象填充它？

Question

我想創建一個構造函數來創建一個數組並用自定義對象填充該數組。這個數組將代表一副牌。

public class DeckOfCards { 
public static Card[] deck = new Card[52]; 

//constructor 
DeckOfCards(){ 
    Card[] deck = new Card[52]; 

    deck[0]=new Card("Ace","Clubs"); deck[1]=new Card("Two","Clubs"); 
    deck[2]=new Card("Three","Clubs");..(ect)...deck[49]=new 
    Card("Jack","Diamonds"); 
    deck[50]=new Card("Queen","Diamonds"); deck[51]=new Card("King","Diamonds"); 
} 

我覺得這應該構造函數創建一個數組，並與卡對象填充它，但它不承認從DeckOfCards（）作爲數組實例化的任何對象。

Answer 1

您有一個範圍的問題，因爲你是在構造函數中再次

Card[] deck = new Card[52]; 

宣佈，留下不影響全球的成員，請改用甲板對象....（順便說一下，沒有必要靜態對象...）

DeckOfCards(){ 

    deck[0]=new Card("Ace","Clubs"); deck[1]=new Card("Two","Clubs"); 
    deck[2]=new Card("Three","Clubs");..(ect.).deck[49]=new 
    Card("Jack","Diamonds"); 
    deck[50]=new Card("Queen","Diamonds"); deck[51]=new Card("King","Diamonds"); 
} 

Answer 2

刪除線，這將是細：
卡[]甲板=新卡[52];

Answer 3

您正在構造函數中再次聲明甲板。我會這樣初始化卡組。迭代通過兩個數組，最簡單的一個。

DeckOfCards(){ 

    suit = ['Hearts','Diamonds','Clubs','Spades']; 
    number=['Ace','One','Two','Three','Four','Five','Six','Seven','Eight','Nine','Ten','Jack','Queen','King']; 

    for (int i=0;i<4;i++){ 
     for (int j=0;j<13;j++){ 
      deck[i+j]=new Card(number[j],suit[i]); 
     } 
    } 
} 

希望這有助於！

Answer 4

首先，您不需要在構造函數中再次初始化deck。只需使用您定義的類級變量即可。

二，deck不應該是static，所以刪除那個單詞。

第三，公開構造函數。

最後但並非最不重要的，你應該更聰明地初始化甲板。

public class DeckOfCards { 
    public Card[] deck = new Card[52]; 

    //constructor 
    public DeckOfCards(){ 
     String[] numbers = { "Ace", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten", "Jack", "Queen", "King" }; 
     String[] suits = { "Spades", "Clubs", "Diamonds", "Hearts" }; 
     int i = 0; 
     for (String suit: suits) { 
      for (String number: numbers) { 
       deck[i] = new Card(number, suit); 
       i++; 
      } 
     } 
    } 
}