Java Help

[ilikemoneygreen]

What am I doing wrong? i cant seem to get the second dialog box to popup to enter the value. I could get it to work just in the command prompt using System.out.print but its not working out with the dialog box.

Code:

/**Area of rectangle *//* ilikemoneygreen
 * CIS163 29843
 * August 24, 2012
 */
 import java.util.Scanner; // scanner package
 import javax.swing.JOptionPane;
 public class RectangleArea {
     public static void main(String[] args) {
         //input the length and width
         Scanner input = new Scanner(System.in);


         //prompt user for length
         JOptionPane.showInputDialog(null, "Enter the length : " , "Length" , JOptionPane.INFORMATION_MESSAGE);
         double length = input.nextDouble();
         //Prompt user for Width
         JOptionPane.showInputDialog(null, "Enter the width : " , "Width" , JOptionPane.INFORMATION_MESSAGE);
         double width = input.nextDouble();


         //calculate area
         double area = length * width;
         //Display the results
         System.out.println("The area of a Rectangle with a width of " + width + " and a length of " + length + " is " + area); 
     }
 }

If you help me, ill give you a cyber hug.

[Rich]

This is clearly an assignment/lab work so I cannot give you the answer but I can give you a pointer. Think carefully about the inputs your program is requesting, it is asking for 4 different inputs in this order:

1. Dialog box
   
2. Command prompt
   
3. Dialog box
   
4. Command prompt
   

Use your program as such.

[ilikemoneygreen]

I surpassed my actual homework, that was just helloworld, which i aced i think. Im working a chapter ahead because it seems pretty fun. im creating extra programs for me to do. The book showed the area for a circle but only using input from a command prompt. i thought it would be cool to have the dialog box to enter in so im attempting the impossible. I think my problem is the book mentioned the JOptionPane in a sidenote, but im not sure how it all works. Im thinking with your hint but im not sure what you mean about command prompt. i got the 1 and 3. and i know i have to enter the inputs which i also declare a variable at the same time. i guess im getting lost on the command prompt part? should i be declaring my variable earlier?

//Dialog box for length

JOptionPane.showInputDialog(null, "Enter the length : " , "Length" , JOptionPane.INFORMATION_MESSAGE);

double length = input.nextDouble();

//Dialog box for width

JOptionPane.showInputDialog(null, "Enter the width : " , "Width" , JOptionPane.INFORMATION_MESSAGE);

double length = input.nextDouble();

[Rich]

[COLOR=#3E3E3E][I]//Dialog box for length[/I][/COLOR]
[COLOR=#3E3E3E][I]JOptionPane.showInputDialog(null, "Enter the length : " , "Length" , JOptionPane.INFORMATION_MESSAGE);
[/I][/COLOR][COLOR=#008000]//Command prompt input for length[/COLOR]
[COLOR=#3E3E3E][I]double length = input.nextDouble();[/I][/COLOR]
[COLOR=#3E3E3E][I]//Dialog box for width[/I][/COLOR]
[COLOR=#3E3E3E][I]JOptionPane.showInputDialog(null, "Enter the width : " , "Width" , JOptionPane.INFORMATION_MESSAGE);
[/I][/COLOR][COLOR=#008000]//Command prompt input for width[/COLOR]
[COLOR=#3E3E3E][I]double width = input.nextDouble();
[/I][/COLOR]

Your code still includes the commands required for input from the command prompt. Therefore after you use your first dialog box, your program then waits for you to input a value using the command prompt.

[bsalis]

    public static void main(String[] args) {
        //prompt user for length
        String inputValue = JOptionPane.showInputDialog(null, "Enter the length : " , "Length" , JOptionPane.INFORMATION_MESSAGE);
        double length = Double.parseDouble(inputValue);
        //Prompt user for Width
        inputValue = JOptionPane.showInputDialog(null, "Enter the width : " , "Width" , JOptionPane.INFORMATION_MESSAGE);
        double width = Double.parseDouble(inputValue);

        //calculate area
        double area = length * width;
        //Display the results
        System.out.println("The area of a Rectangle with a width of " + width + " and a length of " + length + " is " + area); 
    }

[ilikemoneygreen]

the code for entering the command prompt is

 import java.util.Scanner; // scanner package
 public class area3 {
 	public static void main(String[] args) {
 		//Scanner object creation 
 		Scanner input = new Scanner(System.in);
 		//prompt user for legth
 		System.out.print("Enter the lenth : ");
 		double length = input.nextDouble();
                //prompt user for width
 		System.out.print ("Enter the Width : ");
 		double width = input.nextDouble();

 		//calculate area
 		double area = length * width;
 		//Display the results
 		System.out.println("The area of a Rectangle with a width of " + width + " and a length of " + length + " is " + area); 
 	}
 }

i think ive got that worked out since it runs nicely.

but then i thought that the system.out.print forcing it to go through the command prompt. So with it doing JOptionPane should it run just in the dialog box? The first dialog box has an input area so it appeared to be working. but you are SO right, its waiting for the for me to enter the numbers in the command prompt. my problem lies within getting the JOptionPane to accept the input and deleting the inputs for the command prompt. Thank You. now i just gotta do it.

[ilikemoneygreen]

    public static void main(String[] args) {
        //prompt user for length
        String inputValue = JOptionPane.showInputDialog(null, "Enter the length : " , "Length" , JOptionPane.INFORMATION_MESSAGE);
        double length = Double.parseDouble(inputValue);
        //Prompt user for Width
        inputValue = JOptionPane.showInputDialog(null, "Enter the width : " , "Width" , JOptionPane.INFORMATION_MESSAGE);
        double width = Double.parseDouble(inputValue);

        //calculate area
        double area = length * width;
        //Display the results
        System.out.println("The area of a Rectangle with a width of " + width + " and a length of " + length + " is " + area); 
    }

That works !

String inputValue = and Double.parseDouble(inputValue); thats so cool! Thanks. You both get Cyber hugs! [ATTACH=CONFIG]31837[/ATTACH]

[Rich]

So with it doing JOptionPane should it run just in the dialog box? The my problem lies within getting the JOptionPane to accept the input and deleting the inputs for the command prompt. Thank You. now i just gotta do it.

Exactly, I am glad you understand what was wrong with your first attempt. Happy coding!