Question

/* Program Name: BadDate.java

Function: This program determines if a date entered by the user is valid.

Input: Interactive

Output: Valid date is printed or user is alerted that an invalid date was entered.

*/

import java.util.Scanner;

public class BadDate

{

public static void main(String args[])

{

// Declare variables

Scanner userInput = new Scanner (System.in);

String yearString;

String monthString;

String dayString;

int year;

int month;

int day;

boolean validDate = true;

final int MIN_YEAR = 0, MIN_MONTH = 1, MAX_MONTH = 12, MIN_DAY = 1, MAX_DAY = 31;

// This is the work of the housekeeping() method

// Get the year, then the month, then the day

Scanner input = new Scanner(System.in);

// variable = input.nextLine();

System.out.println("Enter the Month");

monthString = input.nextLine();

System.out.println("Enter the Day");

dayString = input.nextLine();

System.out.println("Enter the Year");

yearString = input.nextLine();

// Convert Strings to integers

month = Integer.parseInt(monthString);

day = Integer.parseInt(dayString);

year = Integer.parseInt(yearString);

// This is the work of the detailLoop() method

// Check to be sure date is valid

if( year <= MIN_YEAR ) // invalid year

validDate = false;

if ( month < MIN_MONTH || month > MAX_MONTH ) // invalid month

validDate = false;

if ( day < MIN_DAY || day > MAX_DAY ) // invalid day

validDate = false;

// This is the work of the endOfJob() method

// Test to see if date is valid and output date and whether it is valid or not

if( validDate == true )

{ System.out.println("(month)/ (day)/ (year) is a valid date");

// Output statement

}

else

{

System.out.println("(month)/ (day)/ (year) is an invalid date");

// Output statement

}

} // end of main() method

} // end of BadDate class

HOW DO I GET AN INVALID AND VALID INPUT?

Answer 1

Note: I have highlighted the modified code . Do Check it.

Code to copy:

   /* Program Name: BadDate.java
   Function: This program determines if a date entered by the user is valid.
   Input: Interactive
   Output: Valid date is printed or user is alerted that an invalid date was entered.
   */

   import java.util.Scanner;
   import javax.swing.JOptionPane;

   public class BadDate
   {
       public static void main(String args[])
       {
           // Declare variables
           Scanner userInput = new Scanner (System.in);
           String yearString;
           String monthString;
           String dayString;
           int year;
           int month;
           int day;
           boolean validDate = true;
           final int MIN_YEAR = 0, MIN_MONTH = 1, MAX_MONTH = 12, MIN_DAY = 1, MAX_DAY = 31;
           // This is the work of the housekeeping() method
           // Get the year, then the month, then the day
           Scanner input = new Scanner(System.in);
           // variable = input.nextLine();
           System.out.println("Enter the Month");
           monthString = input.nextLine();
           System.out.println("Enter the Day");
           dayString = input.nextLine();
           System.out.println("Enter the Year");
           yearString = input.nextLine();
           // Convert Strings to integers
           month = Integer.parseInt(monthString);
           day = Integer.parseInt(dayString);
           year = Integer.parseInt(yearString);
           // This is the work of the detailLoop() method
           // Check to be sure date is valid
           if( year <= MIN_YEAR ) // invalid year
               validDate = false;
           if ( month < MIN_MONTH || month > MAX_MONTH ) // invalid month
               validDate = false;
           if ( day < MIN_DAY || day > MAX_DAY ) // invalid day
               validDate = false;
           // This is the work of the endOfJob() method
           // Test to see if date is valid and output date and whether it is valid or not
           if( validDate == true )
           {
               System.out.println(month+"/"+day+"/"+year + " is a valid date");
               // Output statement
           }
           else
           {
              System.out.println(month+"/"+day+"/"+year + " is an invalid date");
               // Output statement
           }
       }// end of main() method
   } // end of BadDate class

Output Screenshot: