Did you immediately notice the bug in my above code? If not, hopefully you get my point. Compared to array.sum() was the above code more or less clear? I

Did you immediately notice the bug in my above code? If not, hopefully you get my point. Compared to array.sum() was the above code more or less clear? Is it more or less prone to bugs? When reading, which code will you have a quicker understanding of the intent? And if you did notice the the first bug, did you notice the second bug?