在java程序中创建方法

Question

I can't seem to figure out how to declare these methods without running into some kind of compiling error with the hiddenexpression. The first method about creating the game I have is fine. I left it in a non-method format so it can compile. Any tips would be great!

package com.company;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {

    Scanner scnr = new Scanner(System.in);

    String expr, player1Name, String player2Name;
    int player1NumGuesses = 0, player2NumGuesses = 0;

    System.out.println("Player 1, what is your name?");

    player1Name = scnr.nextLine();

    System.out.println("Player 2, what is your name?");
    player2Name = scnr.nextLine();

    System.out.println("Player 1 will be the contestant first and player 2 will be the challenger.");

    System.out.println("Then you will change roles for the second round.");
//Method 1: Replace for loop with two calls to playGame, switching     //    contestant and challenger after 1st game


    for (int j = 1; j <= 2; j++) {
        System.out.println("Contestant, turn away from the computer");
        System.out.println("Challenger, type an expression to be guessed.");
        expr = scnr.nextLine();

   //Method 2:make phrase hidden 


        StringBuffer hiddenExpr = new StringBuffer(expr);
        for (int i = 0; i < expr.length(); i++) 
            if (expr.charAt(i) == '\'' || expr.charAt(i) == ' ')
                hiddenExpr.setCharAt(i, expr.charAt(i));
            else
                hiddenExpr.setCharAt(i, '*');

                System.out.println("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");
        System.out.println("Contestant, here is your clue:");
        boolean guessed = false;
        int numGuesses = 0;
        char characterGuess;
        boolean found;
        String exprGuess;
        while (guessed == false && numGuesses < 26) {
            System.out.println(hiddenExpr);
            System.out.println("Contestant, guess a character");
            characterGuess = scnr.nextLine().charAt(0);
            numGuesses++;


     //Method 3, checkForCharacter:


            found = false;
            for (int i = 0; i < expr.length(); i++) {
                if (expr.charAt(i) == characterGuess) {
                    hiddenExpr.setCharAt(i, characterGuess);
                    found = true;
                }
            }
            if (found && expr.equals(hiddenExpr.toString())) {
                System.out.println("You've got the whole thing!");
                if (j == 1)
                    player1NumGuesses = numGuesses;
                else
                    player2NumGuesses = numGuesses;
                guessed = true;
            }


            else if (found) {

                System.out.println("Good for you!! That letter is in the expression.");
                System.out.println("This is what you have so far:");
                System.out.println(hiddenExpr);
                System.out.println("Guess the whole expression");
                exprGuess = scnr.nextLine();
                if (exprGuess.equals(expr)) {
                    System.out.println("You're right!");
                    if (j == 1)
                        player1NumGuesses = numGuesses;
                    else
                        player2NumGuesses = numGuesses;
                    guessed = true;
                }


                else
                    System.out.println("No, you didn't guess the right expression.");
            }
            else
                System.out.println("No, that character is not in the expression.");
        } //End while loop guessing up to 26 times
    } //End for loop going 2 times, to let each contestant have a turn


    System.out.println("Player 1 took " + player1NumGuesses + " guesses.");
    System.out.println("Player 2 took " + player2NumGuesses + " guesses.");
    if (player1NumGuesses < player2NumGuesses) 
        System.out.println("Player 1 wins!") 
    else if (player2NumGuesses < player1NumGuesses) 
        System.out.println("Player 2 wins!");
    else System.out.println("It's a tie!");
} //End main
}  //End program

My take at it.

package com.company;
import java.util.Scanner;

public class Main {
    public static String hiddenExpression(String hidden){

        StringBuffer hiddenExpr = new StringBuffer(hidden);

        for (int i = 0; i < hidden.length(); i++)
            if (hidden.charAt(i) == '\'' || hidden.charAt(i) == ' ')
                hiddenExpr.setCharAt(i, hidden.charAt(i));
            else {
                hiddenExpr.setCharAt(i, '*');

                System.out.println("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");
            }return null;}
    public static void  checkChar(char characterGuess){
        Scanner scnr = new Scanner(System.in);
        boolean guessed = false;
        String expr="";

        int numGuesses = 0;
        int numguesses_contestant;

        boolean found;
        String exprGuess;
        String hiddenExpr = hiddenExpression(expr);
        numGuesses++;
        found = false;
       for (int i = 0; i < expr.length(); i++) {
           if (expr.charAt(i) == characterGuess) {
          hiddenExpression(expr);
               found = true;
            }

        if (found && expr.equals(hiddenExpr.toString())) {
            System.out.println("You've got the whole thing!");
            if (i == 1)
                numguesses_contestant = numGuesses;

        } else if (found) {
            System.out.println("Good for you!! That letter is in the expression.");
            System.out.println("This is what you have so far:");
            System.out.println(hiddenExpr);
            System.out.println("Guess the whole expression");
            exprGuess = scnr.nextLine();
            if (exprGuess.equals(expr)) {
                System.out.println("You're right!");
                if (i == 1)
                    numguesses_contestant = numGuesses;

            } else
                System.out.println("No, you didn't guess the right expression.");
        } else
            System.out.println("No, that character is not in the expression.");

    }}

//------------------------------------------------------------------------------------------------------------------//


    public  static int playGame(String contestant, String challenger, int numGuesses) {
        Scanner scnr= new Scanner(System.in);
        boolean guessed = true;
        String expr;

        int numguesses_contestant=0;
        for (int j = 0; j <= 1; j++) {
            System.out.println("Contestant, turn away from the computer");
            System.out.println("Challenger, type an expression to be guessed.");
            expr = scnr.nextLine();

           hiddenExpression(expr);

            System.out.println("Contestant, here is your clue:");

            while (guessed == false && numGuesses < 26) {
                boolean hiddenExpr=false ;
                System.out.println(hiddenExpr);
                System.out.println("Contestant, guess a character");
                char characterGuess = scnr.nextLine().charAt(0);
                numGuesses++;

                checkChar(characterGuess);

            } //End while loop guessing up to 26 times
        } //End for loop going 2 times, to let each contestant have a turn
    return numguesses_contestant; }
    //--------------------------------------------------------------------------------------------------------------------
     public static void main(String[] args) {Scanner scnr = new     Scanner(System.in);
        String player1;
        String player2;
        int n=0;
        int m =0;
        System.out.println("Welcome to Wheel of Fortune.");
        System.out.println("Player 1 enter your name");
        player1 = scnr.nextLine();
        System.out.println("Player 2 enter your name");
        player2=scnr.nextLine();
        playGame(player1, player2, n);
        playGame(player2, player1, m);

        if (n>m) {
            System.out.println(player1 + " wins!");
        }
        else if (n==m) {
            System.out.println("It's a tie!");}
        else{
            System.out.println(player2 + " wins!");
        }
    }
}

EDIT: for methods

1. playGame This method takes as input the names of the contestant and challenger and has them play a game. Thus, you need to call this method twice, allowing each player to guess an expression. This replaces the for loop that executes twice.

2. makeHiddenExpression This method takes the expression typed in by the challenger and makes another "hidden expression" by putting asterisks (*) where there are letters.

3. checkForCharacter This methods checks to see if a guessed character is in the expression, inserts it in the hidden expression everywhere it should be, and returns true if the character was found.

Answer 1

There are two problems with your code. The first is in line 6.

String expr, player1Name, String player2Name; cannot compile. It should be: String expr, player1Name, player2Name;

The second is in line 78. You forgot the semicolon.

When a code doesn't compile, it's a good idea to look at the type of error message(s) and what line(s) of code the error(s) are on. Error messages are there to give you an idea of what's going on and where the problem is.

Answer 2

Suggestions:

• The meat of your code will be in your playGame method.
• Don't pass in n or m into your methods as that is useless and will not change n or m 's values in the main method.
• Have the playGame return an int (you do that), but don't ignore the int returned! Set it equal to an int variable so you can compare the scores of the two players. ie, int n = playGame(player1, player2);
• It looks like your playGame method will need to do user interaction -- you might want to also pass your Scanner object into this method so you don't create multiple Scanners. This may not be completely necessary, but is something I would do.
• The hiddenExpression(...) method should have no System.out.println(...) statements within it. It should create and return a String and that's it. The playGame method will call this method, assign its result to a String variable, and thenwill then display its result within a println statement. Alternatively, you could have the playGame method call System.out.println(hiddenExpression(challengerExpression)); .
• The checkChar method should not be using a Scanner at all.
• It should not have any println's within it.
• All it should do is to check if the char passed within it is an as-yet unguessed char, it should update a static class field, hiddenExpression, so that it displays the char if it is in fact an unguessed char (but it should not display the hiddenExpression), and it should return true or false depending on if the char passed into it is an as yet unguessed char.