我正在参加初学者的 Java 类(class)。我必须创建一张卡片。然后创建一副牌和一些方法,然后进行测试。
我的卡类别如下
import java.util.*;
public class Card
{
public final static int ACE = 1;
public final static int TWO = 2;
public final static int THREE = 3;
public final static int FOUR = 4;
public final static int FIVE = 5;
public final static int SIX = 6;
public final static int SEVEN = 7;
public final static int EIGHT = 8;
public final static int NINE = 9;
public final static int TEN = 10;
public final static int JACK = 11;
public final static int QUEEN = 12;
public final static int KING = 13;
public final static int CLUBS = 1;
public final static int DIAMONDS = 2;
public final static int HEARTS = 3;
public final static int SPADES = 4;
private final static int NUM_FACES = 13;
private final static int NUM_SUITS = 4;
private int face, suit;
private String faceName, suitName;
private int myInt1, myInt2;
Random rand = new Random();
//-----------------------------------------------------------------
// Creates a random card.
//-----------------------------------------------------------------
public Card ()
{
face = rand.nextInt(4) + 1;
setFaceName();
suit = rand.nextInt(13) + 1;
setSuitName();
}
//-----------------------------------------------------------------
// Sets the string representation of the face using its stored
// numeric value.
//-----------------------------------------------------------------
private void setFaceName()
{
switch (face)
{
case 1:
faceName = "Ace";
break;
case 2:
faceName = "Two";
break;
case 3:
faceName = "Three";
break;
case 4:
faceName = "Four";
break;
case 5:
faceName = "Five";
break;
case 6:
faceName = "Six";
break;
case 7:
faceName = "Seven";
break;
case 8:
faceName = "Eight";
break;
case 9:
faceName = "Nine";
break;
case 10:
faceName = "Ten";
break;
case 11:
faceName = "Jack";
break;
case 12:
faceName = "Queen";
break;
case 13:
faceName = "King";
break;
}
}
//-----------------------------------------------------------------
// Sets the string representation of the suit using its stored
// numeric value.
//-----------------------------------------------------------------
private void setSuitName()
{
switch (suit)
{
case 1:
suitName = "Clubs";
break;
case 2:
suitName = "Diamonds";
break;
case 3:
suitName = "Hearts";
break;
case 4:
suitName = "Spades";
break;
}
}
//-----------------------------------------------------------------
// Determines if this card is higher than the passed card. The
// second parameter determines if aces should be considered high
// (beats a King) or low (lowest of all faces). Uses the suit
// if both cards have the same face.
//-----------------------------------------------------------------
public boolean isHigherThan (Card card2, boolean aceHigh)
{
boolean result = false;
if (face == card2.getFace())
{
if (suit > card2.getSuit())
result = true;
}
else
{
if (aceHigh && face == ACE)
result = true;
else
if (face > card2.getFace())
result = true;
}
return result;
}
//-----------------------------------------------------------------
// Determines if this card is higher than the passed card,
// assuming that aces should be considered high.
//-----------------------------------------------------------------
public boolean isHigherThan (Card card2)
{
return isHigherThan (card2, true);
}
//-----------------------------------------------------------------
// Returns the face (numeric value) of this card.
//-----------------------------------------------------------------
public int getFace ()
{
return face;
}
//-----------------------------------------------------------------
// Returns the suit (numeric value) of this card.
//-----------------------------------------------------------------
public int getSuit ()
{
return suit;
}
//-----------------------------------------------------------------
// Returns the face (string value) of this card.
//-----------------------------------------------------------------
public String getFaceName ()
{
return faceName;
}
//-----------------------------------------------------------------
// Returns the suit (string value) of this card.
//-----------------------------------------------------------------
public String getSuitName ()
{
return suitName;
}
//-----------------------------------------------------------------
// Returns the string representation of this card, including
// both face and suit.
//-----------------------------------------------------------------
public String toString ()
{
return getFaceName() + " of " + getSuitName();
}
}
我的牌组类如下
import java.util.*;
public class DeckOfCards
{
private Card deckOfCards[];
private int currentCardUsed;
private final int NumberOfCards = 52;
private int nextCard;
private Random rand;
String myString = "All Cards have been dealt.";
public DeckOfCards()
{
deckOfCards = new Card[NumberOfCards];
currentCardUsed = 0;
rand = new Random();
for(int index = 0; index < deckOfCards.length; index ++)
{
deckOfCards[index] = new Card();
}
}
public void shuffleCards()
{
currentCardUsed = 0;
for(int newCard = 0; newCard < deckOfCards.length; newCard ++)
{
int nextCard = rand.nextInt(NumberOfCards);
Card temporaryDeck = deckOfCards[newCard];
deckOfCards[newCard] = deckOfCards[nextCard];
deckOfCards[nextCard] = temporaryDeck;
}
}
public Card dealCard()
{
if(currentCardUsed < deckOfCards.length)
{
return deckOfCards[currentCardUsed ++];
}
else
{
return null;
}
}
}
我的驱动程序类如下
public class DeckTester
{
public static void main(String [] args)
{
DeckOfCards deck = new DeckOfCards();
deck.shuffleCards();
System.out.println(deck.dealCard());
System.out.println(deck.dealCard());
System.out.println(deck.dealCard());
System.out.println(deck.dealCard());
System.out.println(deck.dealCard());
System.out.println(deck.dealCard());
System.out.println(deck.dealCard());
System.out.println(deck.dealCard());
System.out.println(deck.dealCard());
}
}
输出:
Two of null
Ace of Hearts
Two of null
Four of null
Ace of null
Ace of Spades
Two of Diamonds
Ace of Clubs
Ace of null
任何关于为什么并非所有卡片都有值(value)的帮助将不胜感激,
最佳答案
简单错误:
改变
public Card ()
{
face = rand.nextInt(4) + 1;
setFaceName();
suit = rand.nextInt(13) + 1;
setSuitName();
}
到
public Card ()
{
face = rand.nextInt(13) + 1;
setFaceName();
suit = rand.nextInt(4) + 1;
setSuitName();
}
其他建议:
- 使用枚举,而不是魔法数字,这样就不会出现这种困惑。
- 不要随机创建牌,创建完整的牌组并洗牌。
关于java - 输出为空,而其他则不为空,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/33772173/