Question

Extend this date validation program, so that it checks for valid leap years (in which the month February has 29, instead of 28, days). A leap year is any year that is divisible by 4 but not divisible by 100, unless it is also divisible by 400. Do not allow February to have 29 days on years that are not leap years.

**Please view both photos for the entire code and post new code with the leap year modification. Thank you!

import java.util.Scanner; public class IC07_HackerChallenge { public static void main (String[] args) { new Scanner (System.in); Scanner kb System.out.println("Please enter date in form MM/DD/YYYY"); String inputDate String monthPart kb.nextLine (); inputDate.substring(0, 2); = Integer.parseInt (monthPart); inputDate.substring (3, 5); int month = String dayPart int day = Integer.parseInt (dayPart); input Date.substring (6); Integer.parseInt (yearPart); String yearPart int year int no days System.out.println (); if (month >= 1 && month <= 12) { switch (month) { case 4: case 6: case 9: case 11: no_days break 30; case 2: no_days break 28 case l: case 3: case 5: case 7: case 8: case 10:

Answer 1

Below I've modified your code for checking leap year, I have not changed your logic.

//filename: IC07_HackerChallenge.java

package test;

import java.util.Scanner;

public class IC07_HackerChallenge {

   public static void main(String[] args) {
       Scanner kb = new Scanner(System.in);
           System.out.println("Please enter date in form MM/DD/YYYY");
           String inputDate = kb.nextLine();
           String monthPart = inputDate.substring(0, 2);
           int month = Integer.parseInt(monthPart);
           String dayPart = inputDate.substring(3, 5);
           int day = Integer.parseInt(dayPart);
           String yearPart = inputDate.substring(6);
           int year = Integer.parseInt(yearPart);
           int no_days = 0;
           System.out.println();
           if(month >= 1 && month <=12) {
               switch(month) {
               case 4:
               case 6:
               case 9:
               case 11:
                   no_days = 30;
                   break;
               case 2:
                   // leap year if divisible by 4 but not divisible by 100, unless it is also divisible by 400
                   if((year%4 == 0 && year%100 != 0) || year%400 == 0)
                       no_days = 29;
                   else
                       no_days = 28;
                   break;
               case 1:
               case 3:
               case 5:
               case 7:
               case 8:
               case 10:
               case 12:
                   no_days = 31;
                   break;
               }
               if (year >= 1000) {
                   if(no_days >= day && day >= 1)
                       System.out.println("The date you entered is valid!");              
                   else
                       System.out.println("Invalid day");
               } else {
                   System.out.println("Invalid year");
               }
           } else {
               System.out.println("Invalid month");
           }  
           kb.close();
   }
}

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