Adding Odd Numbers Using Recursive

[TheComputerGuy]

Just want to be clear, this is practice, not homework.

I'm attempting to understand this a bit better...but I'm a bit lost as what to use for my test...and what exactly will help me get to the base case.

Here is what I have so far

public class int SumOddN (int ar[], int n)
if ar.length == 0 || ar == null || ar.lenth <= n)
{
return 0;
}

if ar[n] % 2 == 0
{
return SumOddN(ar,n-1);
else return SumOddN(ar,n+1)+ar[n];
}


}


public static void main(String[] args)
{

int ar[]= {0,1,2,3,4,5};
System.out.println(SummOddN(ar,2));
System.out.println(SummOddN(ar,3));

}




}

[adarshcu]

First there are lots of typo's in your program. Remove them.

Your class cannot return an int. Your method should

public class void MyClass{

public static int myOddNoSumFunction(args){
 // functionality
}
public static void main(String[] args)
{
myOddNoSumFunction(myargs);
}

}

Note the usage of static. Try the same without static and check what happens.

It'l do you a lot of good to learn it this way. You may think of using a GUI tool. But be careful to track what is happening when you use one.

[JamesCherrill]

You don't an array for this program - the fact that it's there says that you are right to be learning more about recursion ;-)

Assuming that n is a positive odd integer, the recursive algorithm's pseudocode will look something simple like this:

method sumOdd(n)
  if n==1 return 1   (n<=1 would be that little bit safer)
  else return n + sumOdd(n-2)

I'll leave the Java up to you...

[TheComputerGuy]

The array is what we are testing with...as the array is just the collection.

[JamesCherrill]

Testing what with? What collection?
Your title is "Adding Odd Numbers Using Recursive" - and there's nothing in your original post that reveals any need or relevance for an array. Maybe you can clarifywhat the array is doing here?