java - Why my method being called 3 times after System.in.read() in loop

Question

I have started to learn Java, wrote couple of very easy things, but there is a thing that I don't understand:

public static void main(String[] args) throws java.io.IOException
{
    char ch;

    do 
    {
        System.out.println("Quess the letter");
        ch = (char) System.in.read();
    }
    while (ch != 'q');
}

Why does the System.out.println prints "Quess the letter" three times after giving a wrong answer. Before giving any answer string is printed only once.

Thanks in advance

Answer 1

Because when you print char and press Enter you produce 3 symbols (on Windows): character, carriage return and line feed:

q

You can find more details here: http://en.wikipedia.org/wiki/Newline

For your task you may want to use higher level API, e.g. Scanner:

    Scanner scanner = new Scanner(System.in);
    do {
        System.out.println("Guess the letter");
        ch = scanner.nextLine().charAt(0);
    } while (ch != 'q');