Thread: String and int problem in swing program

I just started programming with Java the other day, so I don't really know all too much. I am making a program that asks you for a day of the month, month, and year, and then tells you what day of the week that is.

import javax.swing.JOptionPane ;
 
public class ChurchAustinA1Q1 {
	public static void main(String[] args) {
		final String PROMPT_DAY = "Enter a day of the month." ;
		final String PROMPT_MONTH = "Enter a month. "  ;
		final String PROMPT_YEAR = "Enter a year. " ;
		final String YYYY ;
		final int DAY ;
		final int MONTH ;
		final int CENTURY ;
		final int YEAR ;
		final int WEEK;
 
		DAY = JOptionPane.showInputDialog(null, PROMPT_DAY) ;
		MONTH = JOptionPane.showInputDialog(null, PROMPT_MONTH) ;
		YYYY = JOptionPane.showInputDialog(null, PROMPT_YEAR) ;
		CENTURY = YYYY.substring(0,2) ;
		YEAR = YYYY.substring(2,4) ;
		if ( MONTH < 3 ) {
			MONTH = MONTH + 12 ;
			YEAR = YEAR - 1 ;
		}
 
		WEEK = ( ( DAY + ( ( ( MONTH + 1 ) * 26 ) / 10 ) ) + YEAR + ( YEAR / 4 ) + ( CENTURY / 4 ) + ( 5 * CENTURY ) ) ;
 
		JOptionPane.showMessageDialog(null, "Week day: " + WEEK ) ;
	}
}

But I get this problem:

C:\Users\Austin\Desktop\ChurchAustinA1Q1.java:24: incompatible types
found   : java.lang.String
required: int
		DAY = JOptionPane.showInputDialog(null, PROMPT_DAY) ;
		                                 ^
C:\Users\Austin\Desktop\ChurchAustinA1Q1.java:25: incompatible types
found   : java.lang.String
required: int
		MONTH = JOptionPane.showInputDialog(null, PROMPT_MONTH) ;
		                                   ^
C:\Users\Austin\Desktop\ChurchAustinA1Q1.java:27: incompatible types
found   : java.lang.String
required: int
		CENTURY = YYYY.substring(0,2) ;
		                        ^
C:\Users\Austin\Desktop\ChurchAustinA1Q1.java:28: incompatible types
found   : java.lang.String
required: int
		YEAR = YYYY.substring(2,4) ;
		                     ^
4 errors
 
Tool completed with exit code 1

But if I change those variables to String, then the WEEK equation won't work because those variables need to be int. It's probably something really simple that I'm missing, but I need help.

Hello, the reason this is happening is because the showInputDialog method returns a string but you are trying to store the return into an int.

DAY = JOptionPane.showInputDialog(null, PROMPT_DAY) ;

If you change the variable DAY to be of type String this will work or you could use Integer.parseInt to parse the String.

// Json