Values in array not stored?

[Damien Sky]

Nevermind, I just forgot to increment n while trying to store the humidity... I do this every time and I suddenly realize what I did wrong when I post it online...

My problem is that after printing humidity[n] in the "Humidity(%)" row, it seems that humidity[n] becomes 0. I checked like this:

System.out.println(humidity[5] + " " + humidity[6]);

In the "Humidity(%)" row, they come out fine, but when I do this, they come out as 0, which I think would explain why my heat indices are consistently lower than the temperature when the temperature is over 80.

My code:

import java.util.Scanner;
import java.io.File;
import java.io.IOException;
public class HeatIndex
{
    public static void main(String[] args) throws IOException
    {
        System.out.printf("%70s", "Heat Index: Key West, Florida");
        System.out.println();
        System.out.println();
        System.out.printf("%60s", "Months");
        System.out.println();
        
        String[] months = {"Jan.", "Feb.", "Mar.", "Apr.", "May", "Jun.", "Jul.", "Aug.", "Sep.", "Oct.", "Nov.", "Dec."};
        
        int length = months.length;
        double[] tempDoubleArray = new double[length];
        int[] humidity = new int[length];
        
        for (int i = 0; i < length; i++)
        {
            if (i == 0)
            {
                System.out.printf("%17s", months[i]);
            }
            else
            {
                System.out.printf("%8s", months[i]);
            }
        }
        
        System.out.println("\n ********************************************************************************************************************************");
        
        File Temp = new File("KeyWestTemp.txt");
        Scanner KeyWestTemps = new Scanner(Temp);
        
        System.out.print("\n Temp(F):");
        
        int n = 0;
        
        while (KeyWestTemps.hasNext())
        {
            tempDoubleArray[n] = KeyWestTemps.nextDouble();
            
            System.out.printf("%8.1f", tempDoubleArray[n]);
            
            n++;
        }
        
        KeyWestTemps.close();
        
        File Humid = new File("KeyWestHumid.txt");
        Scanner KeyWestHumidity = new Scanner(Humid);
        
        System.out.print("\n Humidity(%):");
        
        n = 0;
        
        while (KeyWestHumidity.hasNext())
        {
            humidity[n] = KeyWestHumidity.nextInt();
            
            System.out.printf("%-8d", humidity[n]);
        }
        
        KeyWestHumidity.close();
        
        double heatIndex = 0;
        
        System.out.print("\n HI (F): ");
        
        n = 0;
        
        for (int i = 0; i < length; i++)
        {
            if (tempDoubleArray[n] >= 80.0)
            {
                heatIndex = -42.379 + (2.04901523*tempDoubleArray[n]) + (10.14333127*humidity[n]) - (0.22475541*tempDoubleArray[n]*humidity[n]) - ((6.83783E-3)*tempDoubleArray[n]*tempDoubleArray[n]) -
                ((5.481717E-2)*humidity[n]*humidity[n]) + ((1.22874E-3)*tempDoubleArray[n]*tempDoubleArray[n]*humidity[n]) + ((8.5282E-4)*tempDoubleArray[n]*humidity[n]*humidity[n]) -
                ((1.99E-6)*tempDoubleArray[n]*tempDoubleArray[n]*humidity[n]*humidity[n]);
            }
            else
            {
                heatIndex = tempDoubleArray[n];
            }
            System.out.printf("%8.1f", heatIndex);
            
            n++;
        }
    }
}

[Knute Snortum]

Thanks for keeping up your code and using code tags. Can I make a suggestion about your code?

The general rule is not to have line over 80 characters. This seems short, but it help in a lot of situations.

Lines 78 and 79 are both long and cryptic. The use of "magic numbers" is discouraged. A magic number is one that isn't patently obvious (e.g. 1/2) that is not explained or better yet, stored in a variable. -42.379 may mean something to you, but it doesn't to me.

"tempDoubleArray[]" is not a good name. I can tell it's a double array by looking at the code. What does it do? What is it for?

[Dave Tolls]

Damien Sky wrote:Nevermind, I just forgot to increment n while trying to store the humidity... I do this every time and I suddenly realize what I did wrong when I post it online...

It's the action of of mentally constructing your question that gives your brain a chance to analyse the problem.
I get this all the time when I present a problem I've encountered to a colleague and, just as I'm getting to the end of explaining the problem, go "Ah! That's it!".

[Campbell Ritchie]

Knute Snortum wrote: . . . . A magic number is one that isn't patently obvious (e.g. 1/2) . . .

Agree. It is much quicker to write 0.

[Damien Sky]

That was just the formula I was given.

[Knute Snortum]

Damien Sky wrote:That was just the formula I was given.

Fair enough, but you can still break it into smaller lines and format it a bit. Long lines in programs mess up the screen for some users and they're hard to read.

for (int i = 0; i < length; i++)
        {
            if (tempDoubleArray[n] >= 80.0)
            {
                heatIndex = -42.379 + 
                    (2.04901523*tempDoubleArray[n]) + (10.14333127*humidity[n]) - 
                    (0.22475541*tempDoubleArray[n]*humidity[n]) -
                    ((6.83783E-3)*tempDoubleArray[n]*tempDoubleArray[n]) -
                    ((5.481717E-2)*humidity[n]*humidity[n]) + 
                    ((1.22874E-3)*tempDoubleArray[n]*tempDoubleArray[n]*humidity[n]) + 
                    ((8.5282E-4)*tempDoubleArray[n]*humidity[n]*humidity[n]) -
                    ((1.99E-6)*tempDoubleArray[n]*tempDoubleArray[n]*humidity[n]*humidity[n]);
            }
            else
            {
                heatIndex = tempDoubleArray[n];
            }
            System.out.printf("%8.1f", heatIndex);
            
            n++;
        }

[Damien Sky]

OK. I understand that.