Question

In all the other cases I could find, it was due to code not in a method or incorrect bracketing, however I have checked all these. My code is this;

import java.util.*; 
public class averages {
   public static void main(String[] args) 
   {
      //initializing
      double mean = 0;
      double deviation = 0;
      int i = 0;
      double dataset = new double[10];
      double sum = 0;
      double subdev = 0;
      double subsum = 0;
      double dev = 0;

      //getting the numbers
      for (i = 0; i <= 9 ; i++)
      {
         Scanner input = new Scanner(System.in);
         System.out.println("Enter a number");
         dataset[i] = input.nextDouble();
      }

      //calling the function to get 
      avgarray(dataset[]);
      System.out.println("Average is " + mean);
      devequasion(dataset[]);
      System.out.println("Deviation is " + subdev);
   }
   public static double avgarray(double[] arraydata)
   {
      sum = 0;
      for (i = 0; i <= 9 ; i++)
      {
         sum += arraydata[i];
      }
      mean = sum / 10;
      return mean;
   }

   public static double devequasion(double[] devdata)
   {
      subsum = 0;
      for (i = 0; i <= 9 ; i++)
      {
         subsum += devdata[i]*devdata[i];
      }
      dev = math.sqrt((sum - avgarray(devdata[]))/ 9.0);
      return dev;
   }
}

Everything looks correct, but the errors will not go away.

Answer 1

You have quite a few problems there, such as:

• Your defininition of dataset is incorrect. You create a array of doubles then try to assign that to a single double.
• You pass dataset[] rather than dataset.
• You have variables in avgarray and devequasion that are used but not declared (mean, sum, subsum, i, dev). The fact that these are declared in main is not relevant.
• Also, because they’re only used in the methods, they’re unnecessary in main, other that i of course).
• You don’t import java.util.Scanner for the data input.
• The math package is Math with a capital M.

If you use an IDE like Eclipse, you will find it a lot easier to see and fix these problems. For beginners, that’s a ${DEITY}-send.

By all means pump your code into javac as a final step if you have to (headless builds, compatibility and so forth) but do your initial development with an IDE, you’ll find it much faster.

Here’s a version with all those syntactical problems rectified, and a few other minor tweaks, such as the removal of unnecessary variables:

import java.util.Scanner;

public class testprog {
    public static void main (String[] args) {
        double[] dataset = new double[10];

        for (int i = 0; i <= 9 ; i++) {
            Scanner input = new Scanner (System.in);
            System.out.println ("Enter a number: ");
            dataset[i] = input.nextDouble();
        }

        System.out.println ("Average is " + avgarray (dataset));
        System.out.println ("Deviation is " + devequasion (dataset));
    }

    public static double avgarray (double[] arraydata) {
        double sum = 0;
        for (int i = 0; i <= 9 ; i++)
            sum += arraydata[i];
        return sum / 10;
    }

    public static double devequasion (double[] devdata) {
        double subsum = 0;
        for (int i = 0; i <= 9 ; i++)
            subsum += devdata[i] * devdata[i];
        return Math.sqrt ((subsum - avgarray (devdata)) / 9.0);
    }
}

Don’t use this verbatim if it’s homework, you would be foolish to assume your educators were not actively searching the web for plagiarism.