sghill/underscore — comment on commit c8d320b09c4c0a5afcb93b4c78101533ee6b0de7
File: underscore.js line 134
By sghill:

Dropping the `,0)` does work for all but the empty array case -- if you don't give `_.reduce` a starting value with an empty array, it throws an error.

Currently I'm expecting `_sum.([])` to be 0, but that's possibly non-intuitive?