Iterate over array without #each

not_each.rb

```ruby
n_arr = [1, 2, 3]
#=> [1, 2, 3]

def p_each(arr)
  arr.size.times do |i|
    p arr[i] * 2
  end  
  arr
end  

# p to console 2, 4, 6

p_each(n_arr) 
#=> retval [1, 2, 3]

n_arr 
#=> [1, 2, 3]
```