Question

I am creating a program that will print out digits of pi up to a number specified by the user. I can read the input from the user, I can read the text file, but when I print the number of digits, it prints out the wrong number.

“Pi.txt” contains “3.14159”.
Here is my code:

    package pireturner;

    import java.io.*;
    import java.util.Scanner;

    class PiReturner {

        static File file = new File("Pi.txt");
        static int count = 0;

        public PiReturner() {

        }
        public static void readFile() {
            try {
                System.out.print("Enter number of digits you wish to print: ");
                Scanner scanner = new Scanner(System.in);
                BufferedReader reader = new BufferedReader(new FileReader(file));
                int numdigits = Integer.parseInt(scanner.nextLine());

                int i;
                while((i = reader.read()) != -1) {
                    while(count != numdigits) {
                        System.out.print(i);
                        count++;
                    }
                }

            } catch (FileNotFoundException f) {
                System.err.print(f);
            } catch (IOException e) {
                System.err.print(e);
            }
        }            

        public static void main(String[] args ) {
            PiReturner.readFile();
        }
    }

This will print out “515151” if the user inputs 3 as the number of digits they wish to print. I do not know why it does this, and I am not sure what I am doing wrong, as there are no errors and I have tested the reading method and it works fine. Any help would be gladly appreciated. Thanks in advance.

By the way, casting integer ‘i’ to a char will print out 333 (assuming input is 3).

Answer 1

Your inner loop is not left before outputting numdigit times 3

         while (count != numdigits) {
             System.out.print(i);
             count++;
         }

instead …

    int numdigits = Integer.parseInt (scanner.nextLine ());
    // for the dot
    if (numdigits > 1) 
        ++numdigits;
    int i;

    while ((i = reader.read ()) != -1 && count != numdigits) {
         System.out.print ((char) i);
         count++;
   }