Need help with the code...

Question

The program should accept two inputs from user in form of military time for example (1245). Then it should calculate and display the difference.
For some reason it displays 0's...
Please help.
Thanks.
public class TimeInterval
private int firstHour;
private int firstMin;
private int secondHour;
private int secondMin;
//Constructor
public TimeInterval(String first, String second)
String h1 = first.substring(0,1);
int h2 = Integer.parseInt(h1);
firstHour = h2;
//firstHour = Integer.parseInt(first.substring(0,1));
String m1 = second.substring(2,3);
int m2 = Integer.parseInt(m1);
firstMin = m2;
//firstMin = Integer.parseInt(second.substring(2,3));
String hh1 = first.substring(0,1);
int hh2 = Integer.parseInt(hh1);
secondHour = hh2;
//secondHour = Integer.parseInt(first.substring(0,1));
String mm1 = second.substring(2,3);
int mm2 = Integer.parseInt(mm1);
secondMin = mm2;
//secondMin = Integer.parseInt(second.substring(2,3));
//Methods
public int getHours()
int HourDifference = secondHour - firstHour;
return HourDifference;
public int getMinutes()
int MinutesDifference = secondMin - firstMin;
return MinutesDifference;
import java.util.Scanner;
public class TimeIntervalTest
public static void main(String[] args)
Scanner scanner = new Scanner(System.in);
System.out.print("Enter the First time now:");
String hr = scanner.next();
System.out.print("Enter the Second time now:");
String mn = scanner.next();
System.out.println(hr);
System.out.println(mn);
TimeInterval timeDifference = new TimeInterval(hr, mn);
System.out.println(timeDifference.getHours());
System.out.println(timeDifference.getMinutes());
}

Answer 1

I can't say I understand your code, but for a starter, I think you are misunderstanding method substring:
public class StringExample {
    public static void main(String[] args) {
        String first = "2345";
        String h1 = first.substring(0,1);
        System.out.println(h1);
}