You passed 0 in for the initial value. Is this required? In my solution, I omitted the 0 and it worked well; can you explain where omitting the 0 could cause a problem?

Thanks for sharing your insight!

Did some research on how you used the underscore in the callback function. The callback function is provided an 'index', 'element' and 'array object' parameter values. Per my research, some developers use the underscore to store the value, though essentially say it's not going to be used. Is this correct, or is there some other reason why you're using the underscore? (Wouldn't it be easier to omit the underscore?) Thanks!