Java：如何從System.in.read中排除回車/換行

Question

我對此很陌生，正在研究一個教程，但想通過while循環來欣賞它，以便程序重復執行直到用戶輸入“ K”為止。 不幸的是，當輸入了錯誤的字符時，這似乎讀取了回車和換行符。 這意味着“ WRONG ”被輸出三次而不是一次。 有什么方法可以排除這些字符，以便僅讀取字符？ 提前致謝

class Guess{

    public static void main(String args[])
    throws java.io.IOException {
        char ch, answer ='K';


        System.out.println("I'm thinking of a letter between A and Z.");
        System.out.print("Can you guess it:");
        ch = (char) System.in.read(); //read a char from the keyboard

        while (ch != answer) {
        System.out.println("**WRONG**");
        System.out.println ("I'm thinking of a letter between A and Z.");
        System.out.print("Can you guess it:");
        ch = (char) System.in.read(); //read a char from the keyboard
        if (ch == answer) System.out.println("**Right**");

        }

    }
}

Answer 1

我建議使用Scanner並在用戶點擊return時讀取該行，因為read會將return視為另一個字符，例如：

char answer ='K';
Scanner scanner = new Scanner(System.in);
System.out.println("I'm thinking of a letter between A and Z.");
System.out.print("Can you guess it:");
String ch = scanner.nextLine(); //read a char from the keyboard

while (ch.length() > 0 && ch.charAt(0) != answer) {
    System.out.println("**WRONG**");
    System.out.println ("I'm thinking of a letter between A and Z.");
    System.out.print("Can you guess it:");
    ch = scanner.nextLine();//read a char from the keyboard
}
System.out.println("**Right**");
scanner.close();

Answer 2

這只是陳述令。 嘗試這個

public class Guess {

    public static void main(String args[])
            throws java.io.IOException {
        char ch, answer = 'K';

        System.out.println("I'm thinking of a letter between A and Z.");
        System.out.print("Can you guess it:");
        ch = (char) System.in.read(); //read a char from the keyboard

        while (ch != answer) {


            ch = (char) System.in.read(); //read a char from the keyboard
            if (ch == answer) {
                System.out.println("**Right**");
                break;
            }else{
                System.out.println("**WRONG**");
            }
            System.out.println("I'm thinking of a letter between A and Z.");
            System.out.print("Can you guess it:");

        }

    }

}