til

Reduce initial value is optional.

javascript

You don't need to provide an initial value to the reduce method. That way you're saving one iteration that you may not need.

[1,2,3,4].reduce((previousValue, currentValue) =>
  previousValue + currentValue;
);

The iteration starts assigning 1 to previousValue and 2 to currentValue.

I learnt this from @stefanjudis