Mod and If Statement

**Valerie1067** · 03-25-2012, 07:46 AM

Hi there,

For some reason I can't get my mod to make my variable in the if statement to go up a number. Any help would be appreciated!! it is suppose to add the remainder (if any) and make the numberOfRolls go up by one, did I not do set it correctly? Do you need to see more of the code? 35 is the sqft of the roll btw, and you can only order a whole roll at a time.

Java Code:

numberOfRolls = (roomExtra/35.0)+(roomExtra%35.0);
		if(numberOfRolls >0)
			{
				numberOfRolls = numberOfRolls +1;
			}
				System.out.println("The total number of rolls needed: " + f.format(numberOfRolls));

**subzero1012** · 03-25-2012, 08:00 AM

Hello,
I'm sorry, but the problem statement doesn't appear to be very clear to me. As long as your entire code isn't too long, could you please paste the entire code? I mean, if roomExtra was 71, then numberOfRolls would be 2+1 = 3. Then add another?

**Valerie1067** · 03-25-2012, 08:05 AM

Absolutely! Thank you so much for looking at it!!

Java Code:

import java.util.Scanner;
import java.text.DecimalFormat;

public class WallpaperRolls
	{
	public static void main(String[] args)
		{
	//Create Scanner object
	Scanner input = new Scanner(System.in);

	//Create variables
	float lengthOfRoom;
	float heightOfRoom;
	float widthOfRoom;
	double roomArea, totalArea;
	double roomExtra; 
	double numberOfRolls;
	double totalCost, pricePerRoll;

	DecimalFormat f = new DecimalFormat("0.00");

	//Get room dimensions
	System.out.print("What is the length of the room (in ft)?: ");
	lengthOfRoom = input.nextFloat();

	System.out.print("What is the height of the room (in ft)?: ");
	heightOfRoom = input.nextFloat();
	System.out.print("What is the width of room (in ft)?: ");
	widthOfRoom = input.nextFloat();

	// Get price per roll
	System.out.print("What is the price of the wallpaper?:$");
	pricePerRoll = input.nextDouble();

	//Calculate area
	roomArea = ((2 * lengthOfRoom * heightOfRoom) + (2 * lengthOfRoom * widthOfRoom));

	//Calculate mistakes
	roomExtra = ( roomArea*1.10);

	//Calculate number of rolls
	numberOfRolls = (roomExtra/35.0)+(roomExtra%35.0);
		if(numberOfRolls >0)
			{
				numberOfRolls = numberOfRolls +1;
			}
				System.out.println("The total number of rolls needed: " + f.format(numberOfRolls));
			
	//Calculate total area
	totalArea = roomArea;
	System.out.println("The total area of room is " + f.format(totalArea));

	//Calculate total cost
	totalCost = (numberOfRolls * pricePerRoll);
	System.out.println("The total cost of wallpaper:$" + f.format(totalCost));

	}	
}

**subzero1012** · 03-25-2012, 08:27 AM

Thanks for posting the code. It appears to work as required for me (adds an additional roll inside the if statement). The result I got was 9.14 rolls. I used the following inputs as test conditions.

length = 5
width = 5
height = 5

roomExtra = 110

110/35 = 3.14
110%35 = 5

3.14 + 5 = 8.14

**Valerie1067** · 03-25-2012, 08:30 AM

Ok! thank you very much! I guess I just thought that it should be a whole number and not a decimal number, so I thought that it wasn't working properly. thank you so much for your help!

**subzero1012** · 03-25-2012, 08:37 AM

I've looked at your code a little more closely and something doesn't make sense to me. For example, if my roomExtra was 72 sqft, you would really just need 3 rolls, right? If so, your code would calculate that you would need 5 rolls. Am I missing something here?

**Valerie1067** · 03-25-2012, 08:41 AM

hhhmmm...I didnt realize that! thank you for pointing that out, any suggestions? i am not sure how that is happening. I am very new to Java. Thank you so much for catching that!

**subzero1012** · 03-25-2012, 08:57 AM

//Calculate number of rolls
numberOfRolls = (int) (roomExtra/35.0); //round down to integer
if(roomExtra%35.0 >0) if remainder, add a roll
{ numberOfRolls = numberOfRolls +1; }