java - 如何更新方法中的值？

Question

我构建了一个字符串猜谜游戏，它运行良好，除了当用户输入输入时，输入会检查字符串中的非法字符，如果有，用户必须重新输入新的输入，但输入没有'不在程序中更新。

我尝试将输入值设为全局值，但事实并非如此，该类也由主类调用。

import java.util.Scanner;
public class GuessCharactersInAString {
    static Scanner scan = new Scanner(System.in);
    static String input;
    public static void guessTheString(){
        String response;
        introduction();
        do {
            System.out.println("Please enter a string of words.");
            String input = scan.nextLine();
            legalString(input);
            int inputLength = input.length();
            String charsUsed = " abcdefghijklmnopqrstuvwxyz";
            int charsUsedLength = charsUsed.length();
            String answerString = "?".repeat(inputLength);
            int answerStringLength = answerString.length();


            char[] answerStringChars = answerString.toCharArray();
            char[] charsUsedChars = charsUsed.toCharArray();
            char used = '\u26c7';
            String newAnswerString;
            String newcharsUsedLength;
            boolean gameIsDone = false;
            System.out.println("Guess a letter, only alphabet letters and the space bar please,"
                    + "\n" + "special characters/symbols and numbers are not allowed");
            while (!gameIsDone) {


                String guess = scan.nextLine();
                legalGuess(guess);

                String guessRepeat = guess.repeat(3);
                char guessChar = guessRepeat.charAt(2);

                for (int i = 0; i < answerString.length(); i++) {
                    if (input.charAt(i) == guessChar) {
                        answerStringChars[i] = guessChar;
                    }
                }
                for (int j = 0; j < charsUsed.length(); j++) {
                    if (charsUsed.charAt(j) == guessChar) {
                        charsUsedChars[j] = used;
                    }

                }
                System.out.println("\t\t\t\t\t\t\t" + "Original String: " + input);
                newAnswerString = String.valueOf(answerStringChars);
                System.out.println("\t\t\t\t\t\t\t" + "Guessed String: " + newAnswerString + "\n");
                newcharsUsedLength = String.valueOf(charsUsedChars);
                System.out.println("\t\t\t\t\t\t\t" + "Characters to choose from:" + "\n" + "\t\t\t\t\t\t\t" + newcharsUsedLength);

                if (newAnswerString.equals(input)) {
                    gameIsDone = true;
                }

            }
            System.out.println("Congratulations! You guessed it!");
            System.out.println("Would you like to play again?, please enter yes");
            response=scan.nextLine();
        }
        while (response.equalsIgnoreCase("yes"));
    }

    private static void introduction() {
        System.out.println("\t\t\t\t\t" + "  This game prompts for a string of words.  It \n" +
                "                      then allows the player to guess the characters\n" +
                "                      in the string of words. It keeps track of the \n" +
                "                      characters guessed and tells the player when he\n" +
                "                      wins.");
    }

    private static String legalString (String input){
        input = input.toLowerCase();

        while (input.contains("1") || input.contains("2") || input.contains("3") || input.contains("4") || input.contains("5") || input.contains("6") || input.contains("7") || input.contains("8")
                || input.contains("9") || input.contains("0") || input.contains("!") || input.contains("@") || input.contains("#") || input.contains("$") || input.contains("%") || input.contains("^")
                || input.contains("&") || input.contains("1") || input.contains("1") || input.contains("1") || input.contains("1") || input.contains("1") || input.contains("1") || input.contains("1") ||
                input.contains("&") || input.contains("*") || input.contains("(") || input.contains(")") || input.contains("-") || input.contains("_") || input.contains("=") || input.contains("+") ||
                input.contains("`") || input.contains("~") || input.contains("-") || input.contains("[") || input.contains("{") || input.contains("]") || input.contains("}") || input.contains(";") ||
                input.contains(":") || input.contains("'") || input.contains(",") || input.contains("<") || input.contains(".") || input.contains(">") || input.contains("?") || input.contains("/") ||
                input.contains("|")) {
            System.out.println("Inappropriate value(s), please enter a new value");
            input = scan.nextLine();
        }
        return input;
    }
    private static String legalGuess(String guess){

            int guessLength = guess.length();
            guess=guess.toLowerCase();
        while (guess.contains("1") || guess.contains("2") || guess.contains("3") || guess.contains("4") || guess.contains("5") || guess.contains("6") || guess.contains("7") || guess.contains("8")
                || guess.contains("9") || guess.contains("0") || guess.contains("!") || guess.contains("@") || guess.contains("#") || guess.contains("$") || guess.contains("%") || guess.contains("^")
                || guess.contains("&") || guess.contains("1") || guess.contains("1") || guess.contains("1") || guess.contains("1") || guess.contains("1") || guess.contains("1") || guess.contains("1") ||
                guess.contains("&") || guess.contains("*") || guess.contains("(") || guess.contains(")") || guess.contains("-") || guess.contains("_") || guess.contains("=") || guess.contains("+") ||
                guess.contains("`") || guess.contains("~") || guess.contains("-") || guess.contains("[") || guess.contains("{") || guess.contains("]") || guess.contains("}") || guess.contains(";") ||
                guess.contains(":") || guess.contains("'") || guess.contains(",") || guess.contains("<") || guess.contains(".") || guess.contains(">") || guess.contains("?") || guess.contains("/") ||
                guess.contains("|") || guessLength != 1)
        {

            System.out.println("inappropriate value(s), please enter a new guess");
            guess = scan.nextLine();
            guess=guess.toLowerCase();
            guessLength=guess.length();
        }

        System.out.println("Character read: " + guess);

        return guess;
    }
}

这就是我得到的：

Please enter a string of words
User:112
Inappropriate value(s), please enter a new value
User:The cat in the hat
Guess a letter, only alphabet letters and the space bar please,
special characters/symbols and numbers are not allowed
User:a
                            Original String: 55
                            Guessed String: 55

                            Characters to choose from:
                             abcdefghijklmnopqrstuvwxyz

预期的

                            Original String: The cat in the hat
                            Guessed String: The cat in the hat

                            Characters to choose from:
                             abcdefghijklmnopqrstuvwxyz

标签： javastring

Answer 1

您从中返回新的字符串值，legalString(input)但没有分配它。将此行替换为input = legalString(input);

通话也一样legalGuess()。