Reduce vs Each With Object

Both methods serve the same purpose : from an Enumerator create a single value out of it


Reduce is prefered when you need to produce a simple value because it reduce over the returned value

[1, 2, 3].reduce(:+)
> 3

We can illustrate this simply with this snippet :

[1, 2, 3].reduce do |acc, v|
  acc += v
> 0

Each With Object

Each with object is prefered when you reduce on a hash or some sort of complex object beacause is use the accumulator value and not the returned one

[1, 2, 3].each_with_object({ sum: 0 }) do |v, acc|
  acc[:sum] += v
> {sum: 6}

Fun fact, reduce takes |acc, v| while each_with_object take |v, acc|