Question

我是java的新手，但仍然存在setter和getter的问题。我真的不了解getter和setter的设置。有人能指出我正确的方向吗？

*This is the output i get:* 
your cards are four & jack 
fourjack

*This is the output im looking for:*
your cards are four & jack
14



String[] cards = {"ace","two","three","four","five","six","seven","eight", "nine", "ten", "jack", "queen", "king"};
String card1 = (cards[new Random().nextInt(cards.length)]);
String card2 = (cards[new Random().nextInt(cards.length)]);
System.out.println("your cards are " + card1() + " & "+ card2);
System.out.println(card1 + card2);
}
public static int getCard1() {
    return getCard1();
}

public static void setCard1(int card1) {
    Player.card1 = card1;
}   
public static int getCard2() {
    return getCard2();
}
**strong text**
public static void setCard2(int card2) {
    Player.card2 = card2;
}
}

Answer 1

您应该使用最后一部分中的索引号

String[] cards = {"ace","two","three","four","five","six","seven","eight", "nine", "ten", "jack", "queen", "king"};
int c1 = new Random().nextInt(cards.length);
int c2 = new Random().nextInt(cards.length);
String card1 = (cards[c1]);
String card2 = (cards[c2]);
System.out.println("your cards are " + card1 + " & "+ card2);

c1++;
if (c1>9) c1 = 10;
c2++;
if (c2>9) c2 = 10;

System.out.println(c1+c2);

Answer 2

封装是使类中的成员变量成为私有并提供访问的基本机制之一通过公共方法对这些变量，即setter和getter。如果字段声明为私有，它不能被班级以外的任何人访问，即使不是子班级，从而隐藏了班级中的字段。出于这个原因，封装也被称为＆＃34;数据隐藏＆＃34;。

在这个示例中，您有直接使用的变量，但如果您真的想使用getter和setter，则需要生成/创建它们。我已经更改了你的代码并创建了单独的类来通过getter和setter实现。

class Game {

  private String card1 ;
  private String card2 ;

  private int c1;
  private int c2; 

  String[] cards = {"ace","two","three","four","five","six","seven","eight", "nine", "ten", "jack", "queen", "king"}; 
  int len = cards.length;


    public  String getCard1(){
      return card1;
   }

    public  void setCard1(String cardName1){
      card1 = cardName1;
   }

    public  String getCard2(){
      return card2;
   }

    public void setCard2(String cardName2){
      card2 = cardName2;
   }

    public  int getC1(){
     setC1();
      return c1;
   }

    public void setC1(){
      c1 = new Random().nextInt(len);
   }


    public  int getC2(){
      setC2();
      return c2;
   }

    public void setC2(){
      c2 = new Random().nextInt(len);
   }


    public String getCards(int i) {
        return cards[--i];
    }
}

现在您可以在主类中使用这些getter和setter，如下所示：

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class test
{


    public static void main (String[] args) throws java.lang.Exception
    {
    Game game = new Game();
      //get random numbers
    int a1 = game.getC1();
    int a2 = game.getC2();    
    //get the array values
    game.setCard1(game.getCards(a1));
    game.setCard2(game.getCards(a2));

    System.out.println("Your cards are \n1: " + game.getCard1() + " \n2: "+ game.getCard2());
    //sum logic 
    if (a1>9) a1 = 10;
    if (a2>9) a2 = 10;
    //Output
    System.out.println("Sum of you cards is :");
    System.out.print(a1+a2);
    }
}

因此，您可以使用setter和getter构建代码，从而提高代码的可维护性，灵活性和可扩展性。

您可以查看完整代码here。您可以运行此代码here。

我如何在java中使用setter和getter

2 个答案: