title: All_else method (Ruby)
body: <p>I'm trying to create a method that iterates through an array and add up all of its elements and returns the element that is half of its sum, else it will return nil.</p>
  <p>Examples:</p>
  <pre><code>p all_else_equal([2, 4, 3, 10, 1]) #=&gt; 10, because the sum of all elements is 20
  p all_else_equal([6, 3, 5, -9, 1]) #=&gt; 3, because the sum of all elements is 6
  p all_else_equal([1, 2, 3, 4])     #=&gt; nil, because the sum of all elements is 10 and there is no 5 in the array.
  </code></pre>
  <p>My solution was to iterate through the array and add each element together using a 'sum' variable. Then write a conditional statement stating if half of the sum is included in the arr, then return the element, else return nil. But for what ever reseason I keep getting 'nil'. Can anyone out there tell me why this is wrong? Here's my code:</p>
  <pre><code>def all_else_equal(arr)
    sum = 0
    sum_half = sum / 2  
  
    arr.each_with_index do |ele, i|
      sum += ele    
  
      if sum_half == ele
        return ele
      else
        return nil
      end
    end
  end
  </code></pre>
  <p>console:</p>
  <pre><code>nil
  </code></pre>