Question

我刚刚开始一场战争纸牌游戏。我制作了一副牌，然后需要重新洗牌。无论如何，我将需要.length以后更正。因此，当我使用长度时，当我计算它应该是52时它得到160作为答案。这是代码。

import java.util.List;

public class wargame {
    public static void main(String args[]){
        funtionsforwargame funtionsforwargame=new funtionsforwargame();
        funtionsforwargame.instructions();
        List<String> randomized_deck=funtionsforwargame.get_deck();
        String[] deck_convert = randomized_deck.toArray(new String[0]);
        String deck=java.util.Arrays.toString(deck_convert);
        System.out.println(deck);
        System.out.println(deck.length());

    }

}

此外，get_deck方法创建一个deck作为数组，然后转换为列表字符串并返回它，因为它需要被洗牌。所以我然后把那个返回的列表转换回一个数组，然后确保它给了我甲板，而不是像ghty @ 67843那样的东西。因此，如果有人知道为什么它给我160而不是52，那将是有帮助的。这是get_deck方法，以防你不相信我在列表/数组中有52个。

public class funtionsforwargame {
    public void instructions(){
        System.out.println("Welcome to War!");
        System.out.println("The object of the game is to collect all cards from the other person.");
        System.out.println("Basically, all you do is watch and press any key to go to the next round.");
        System.out.println("Good luck!!!");
    }
    public List<String> get_deck(){
        String new_deck[]={"A","A","A","A","2","2","2","2","3","3","3","3","4","4","4","4","5","5","5","5","6","6","6","6","7","7","7","7","8","8","8","8","9","9","9","9","10","10","10","10","J","J","J","J","Q","Q","Q","Q","K","K","K","K"};
        List<String> list_convert = Arrays.asList(new_deck);
        Collections.shuffle(list_convert);
        return list_convert;
    }

}

提前致谢。

Answer 1

你知道吗：

int[] x = {1,2,3};

和

String y = Arrays.toString(x);

完全不同的东西？

当你做

时

System.out.println(deck);
System.out.println(deck.length());

长度计算逗号，空格和[]，为什么它们与 randomized_deck

中的52张卡相同

你根本就不习惯使用数组，在你的情况下，列表还不错......

只是做

List<String> randomized_deck = funtionsforwargame.get_deck();

System.out.println(randomized_deck);

要分割，您可以使用List#subList(....);

Answer 2

当你这样做时：

String deck=java.util.Arrays.toString(deck_convert);

52号变为160，因为卡10 为2 位数。

您应该打印String[] deck_convert而不是Arrays.toString(deck_convert)。

public class wargame {
    public static void main(String args[]) {
        funtionsforwargame funtionsforwargame = new funtionsforwargame();
        funtionsforwargame.instructions();
        List<String> randomized_deck = funtionsforwargame.get_deck();
        String[] deck_convert = randomized_deck.toArray(new String[0]);
        for(String card : deck_convert)
            System.out.print(card + ",");
        System.out.println(deck_convert.length);
    }
}

Answer 3

这是真的，你可以在这个地方检查：

public class wargame {

    public static void main(String args[]) {
        funtionsforwargame funtionsforwargame = new funtionsforwargame();
        funtionsforwargame.instructions();
        List<String> randomized_deck = funtionsforwargame.get_deck();
        String[] deck_convert = randomized_deck.toArray(new String[0]);
        String deck = java.util.Arrays.toString(deck_convert);
        System.out.println(deck_convert.length);
        System.out.println(deck);
        System.out.println(deck.length());

    }

}

<强>输出：

52
[10, 2, 8, 3, A, 7, 2, 6, 8, 6, 4, K, 3, 9, 10, 3, 5, J, Q, 7, 5, 8, K, J, J, 3, A, 7, 7, 9, 2, 6, K, 4, Q, 9, A, Q, 10, A, 9, 5, K, Q, 5, 6, 8, 10, J, 4, 4, 2]
160

在第一种情况下，length为您提供数组元素的数量。在另一个中，您将获得已转换字符串的实际长度。我们可以通过以下方式轻松检查：

public static void main(String args[]) {
    funtionsforwargame funtionsforwargame = new funtionsforwargame();
    funtionsforwargame.instructions();
    List<String> randomized_deck = funtionsforwargame.get_deck();
    String[] deck_convert = randomized_deck.toArray(new String[0]);
    String deck = java.util.Arrays.toString(deck_convert);
    System.out.println(deck_convert.length);
    System.out.println(deck);
    System.out.println(deck.charAt(4));  // here we take one symbol
    System.out.println(deck.length());

}

<强>输出：

52
[A, 7, 2, A, 2, 2, 5, A, 3, 8, 6, Q, 10, 4, K, 4, J, 3, 5, 7, 8, Q, 7, 5, 10, K, 10, 4, 9, 6, Q, 8, K, 7, 6, 9, J, J, 10, K, 5, 2, 8, 6, J, Q, 3, 4, 9, A, 3, 9]
7
160

我们可以看到命令System.out.println(deck.charAt(4));给了我们**7**。

Java Array.Length不正确

3 个答案: