Java Average Functions

Question

I am new to programming and I am trying to figure out a simple average function. I have written a function to average 3 integers. Now I would like to be able to use any collection class and any number class and get the average. The problem is with these classes you can't use + or / to get the average.

So I am wondering if there are any work-arounds to be able to use these two classes?

here is my first function that works:

package refresh;
import java.util.*;
public class Average {
public static void main( String args[]){
 int a, b, c;
 float average;
 Scanner scanner = new Scanner(System.in);
 System.out.println("Enter First Number");
 a = scanner.nextInt();
 System.out.println("Enter Second Number");
 b = scanner.nextInt();
 System.out.println("Enter Third Number");
 c = scanner.nextInt();
 average = (float)(a+b+c)/3;
 System.out.println("The Average Is "+average );
}
 }

Here what I have so far for my problem:

package refresh;
import java.util.*;
public class Average {
public static void main( String args[]){
 Collection numbers;
 Number count;
 Number average;
 Scanner scanner = new Scanner(System.in);
 System.out.println("Enter Numbers to be averaged");
 numbers = (Collection) scanner.match();
 count++;
 average = numbers/count;
 System.out.println("The Average Is "+average);
}
}

Any help would be great! Thanks for your time!

• Adam Mihalcin: Unfortunately, there's no nice way to get around the difficulty with + and /. Probably your best bet is to pass around an object with methods plus and divide, which encapsulates the + and / logic for a specific numeric type.
• Jayan: if you use double (Scanner.nextDouble ), you cover all numbers. As for + and /, Adam already advised you to go with methods with suitable name.

Answer 1

It makes no sense to convert a String into a number (which is what Scanner does) if you don't know what kind of number you're trying to convert it into.

You can represent pretty much any number as a Double. If you need arbitrary precision, use BigDecimal.

The averaging code can be fully generic over the Number interface; just use the doubleValue method. If you need BigDecimal, then it's more complicated and you probably need to do things involving instanceof.