NumberFormatException when trying to read dates from console input

Question

So I'm trying to find the latest date from a list of dates, but I keep getting a NumberFormatException. Is there any way of resolving this?

import java.util.*;

public class Date
{
    private String date;
    private int day;
    private int month;
    private int year;

    public Date(String date)
    {

        String [] newDate = date.split(" ");

        this.day = Integer.parseInt(newDate[0]);
        this.month = Integer.parseInt(newDate[1]);
        this.year = Integer.parseInt(newDate[2]);
    }

    public boolean isOnOrAfter(Date other)
    {
        if(this.day < other.day)
        {
            return true;
        }
        else if(this.day == other.day && this.month < other.month)
        {
            return true;
        }
        else if(this.day == other.day && this.month == other.month && this.year < other.year)
        {
            return true;
        }
        return false;
    }

    public String toString()
    {
        return day + "/" + month + "/" + year;
    }

    public static void main(String [] args)
    {
        Scanner in = new Scanner(System.in);
        System.out.print("How many dates: ");

        int num = in.nextInt();

        System.out.println("Enter " + num + " dates: ");

        String [] dates = new String[num];

        for(int i = 0; i < dates.length; i++)
        {
            dates[i] = in.nextLine();
        }

        Date latest = new Date(dates[0]);

        for(int i = 0; i < dates.length; i++)
        {
            Date newDates = new Date(dates[i]);
            if(latest.isOnOrAfter(newDates))
            {
                latest = newDates;
            }
        }
        System.out.println(latest);
    }
}

I think its just a tiny problem, but I can't seem to find it. Thanks in advance.

I have a method that checking for the latest date, the logic of the code seems fine to me, if you see any problems in the logic, let me know.

The dates will be input one line at a time, for example:

1 1 1890
1 1 2000
2 1 2000
30 12 1999

The output should be 2/1/2000.

Answer 1

There are two reasons for the NumberFormatException here:

1.You have multiple spaces in your input between the day, month and the year.
2. Scanner's nextInt does not consume the newline. Hence you need to include a dummy nextLine after it. You can read more about this here.

int num = in.nextInt();
in.nextLine(); //To consume the new line after entering the number of dates
System.out.println("Enter " + num + " dates: ");

String [] dates = new String[num];
 ...