Question

我对此非常陌生并且正在完成一个教程，但是希望用一个while循环来使用它，以便程序重复直到用户输入“K”。不幸的是，当输入错误的字符时，这似乎会读取回车符和换行符。这意味着“错误”输出三次而不是一次。有没有办法排除这些，以便只读取字符？提前致谢

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

我建议使用Scanner并在用户点击返回时读取该行，因为read认为返回为另一个字符，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

这只是法令的命令。试试这个

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:");

        }

    }

}

Java：如何从System.in.read中排除回车/换行

2 个答案: