Question

Java program called countDigits– use input file named countDigits.txt Read in a number and a digit. Count the number of times you find the digit in the number. Example: Sent to the method: 10203040586970 0 Returned the number of times it finds a match: 5

Answer 1

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class countDigits {

    public static int countDigit(long number, int digit) {
        if (number == 0) {
            if (digit == 0) {
                return 1;
            } else {
                return 0;
            }
        }
        int count = 0;
        while (number > 0) {
            if (number % 10 == digit)
                ++count;
            number /= 10;
        }
        return count;
    }

    public static void main(String[] args) {
        File file = new File("countDigits.txt");
        try {
            Scanner fin = new Scanner(file);
            long number = fin.nextLong();
            int digit = fin.nextInt();
            System.out.println("Number of occurrences of " + digit + " in " + number + " is " + countDigit(number, digit));
            fin.close();
        } catch (FileNotFoundException e) {
            System.out.println(file.getAbsolutePath() + " is not found!");
        }
    }
}