java - 我如何正确调用我创建的方法以便我能够在另一个中使用它？

Question

我正在用以下方法制作石头、纸、剪刀：

 displayRoundResults()
 displayMatchResults()
 chooseHandShape()
 winningHand()
 //etc

该winningHand()方法比较字符并返回一个值（0,1,2）。在我的displayRoundResults()方法中，我尝试将该winningHand()方法调用到该displayRoundResults()方法中，以便它可以从中获取整数winningHand()，然后根据返回的值添加到玩家的任一分数。

我想我的方法写得很好，我只是停留在如何调用方法上。

public class RockPaperScissors
{
    private final char _YES = 'Y';
    private final int _HIGH_BESTOF = 5;
    // ***********************************************************************

    // central method that holds the majority of the game's logic
    public void playGame()
    {
        char player1, player2; //used to display the handshape from method
        int playToWins;
        int winningHand;
        int p1Score = 0;
        int p2Score = 0;
        int numberOfRounds; 

        while (true) //add loop so that it keeps going until user decides to end the game

        System.out.println("Welcome to Rock, Paper, Scissors..");
        //call playToWins Method to retrieve how many rounds will be played
        //playToWins(scan);

        //will output different outcomes until winner has won x amount of times (the number retrieved from playToWins)
        for (int i = 1; i <= numberOfRounds; i++)
        {
            player1 = chooseHandShape();
            player2 = chooseHandShape();

            //displays rock,paper, or scissor for each player
            System.out.println("P1: " + player1 + " P2: " + player2);

            //winningHand is called to compare the two values and then return an int (0,1,2)
            winningHand = winningHand(player1, player2);

            //displayRoundResult is called to calculate score for each round that is played
            displayRoundResult(p1Score, p2Score);
        }
        //displayMatchResult here
        //
        // majority of code should be here
        //scanner should be here
    }

    // display round results
    private void displayRoundResult(int p1Score, int p2Score)
    {
        int winningHand;
        //properly call winningHand method here

        if (winningHand == 1)
        {
            p1Score++;
        }
        if (winningHand == 2)
        {
            p2Score++;
        }
        //if winning equals ... then p1score goes up by 1 or p2score does
    }

    // display match results
    private void displayMatchResult(int round, int p1Score, int p2Score)
    {
        System.out.println("Player 1 has " + p1Score + " points & Player 2 has " + p2Score + " points"); 
    }

    // get what will be the round goal score
    private int playToWins(Scanner scan)
    {
        int numberOfRounds;

        System.out.println("Play round to? (Max is 5)");
        numberOfRounds = scan.nextInt();

        while (numberOfRounds > _HIGH_BESTOF)
        {
            System.out.println("Please enter a value between 1 and 5, your last input was incorrect!");
            numberOfRounds = scan.nextInt();
        }

        return numberOfRounds;
    }

    // given two hands choose which one wins
    // possible values for either parameter are 'R','P' or 'S'
    // use the RPS rules to determine the winner
    // return 0 for tie, 1 for player 1 win or 2 for player 2 win
    private int winningHand(char player1, char player2)
    {   
        int winningHand;
        char R,P,S;

        //tie
        if (player1 == (player2))
        {
            winningHand = 0;
        }

        //if player 1 wins
        if (player1 == R && player2 == S)
        {
            winningHand =  1;
        }
        if (player1 == S || player2 == P )
        {
            winningHand = 1;
        }
        if (player1 == P || player2 == R)
        {
            winningHand = 1;
        }

        //if player 2 wins
        if (player1 == S || player2 == R)
        {
            winningHand = 2;
        }
        if (player1 == P || player2 == S)
        {
            winningHand = 2;
        }
        if (player1 == R || player2 == P)
        {
            winningHand = 2;
        }

        return winningHand;

    }

    // method that randomly chooses a hand shape
    // returns 'R' for rock, 'P' for paper and 'S' for scissors
    private char chooseHandShape()
    {

        Random cChoice = new Random();
        Random pChoice = new Random();

        //0 = Scissors, 1 = Rock, 2 = Paper

        int cChoiceInt =  cChoice.nextInt(2);
        int pChoiceInt = pChoice.nextInt(2);

        //player 1 randomized
        char pChoice1;
        switch (pChoiceInt)
        {
        case 0:
            pChoice1 = 'S';
            break; 
        case 1:
            pChoice1 = 'R';
            break;
        case 2:
            pChoice1 = 'P';
            break;
        }

        //player 2 randomized
        char cChoice1;
        switch (cChoiceInt)
        {
        case 0:
            cChoice1 = 'S';
            break; 
        case 1:
            cChoice1 = 'R';
            break;
        case 2:
            cChoice1 = 'P';
            break;
        }

        return cChoice1;
        return pChoice1;
    }

    // Yes/No response
    // Returns true if the user enters a 'y' or 'Y'
    //
    private boolean yesResponse(Scanner scan)
    {
        System.out.println("Would you like to play again? Yes(Y) or No(N)?");
        //scan.nextChar();
        return scan.nextLine().toUpperCase().charAt(0) == _YES;
    }
}

标签： java

Answer 1

好的，所以你绝对是编程新手。知道了这一点，我建议尽可能多地阅读/观看有关编程基础知识的指南。

无论如何，正如您可以在此处阅读的那样，您首先需要编写函数的名称（您说对了那部分）。但是，Java 和许多语言中的函数也由括号定义，()如果有参数，则用于传递参数（但即使没有参数，这些仍然是必需的）。此外，在函数返回一个像你一样的值的情况下，如果你想在以后使用它（就像你的情况一样），你需要将它的结果分配给一个变量。这将是一种正确的方法：

int thisRoundWinningHand = winningHand(player1Hand, player2Hand)

但是，请注意，这在您当前的实现中是不正确的，因为您当前在函数中采用类型值char但winningHand()您displayRoundResults()只收到分数？两个玩家作为 type 的值int。此外，变量的名称是不同的，因为您希望轻松区分函数和变量（但在 Java 中不是强制性的）。

关于您的代码还有很多需要指出的地方，这就是为什么我再次敦促您首先阅读适当的指南（我在此处链接的 W3Schools 对初学者有好处，您可以从介绍开始）。

希望能帮助到你