considering reduce vs forEach + object assignment

phivk — Fri, 06 Mar 2020 11:58:52 +0000

Hi folks!

My first post here is a question I'm facing atm, hope you can share some wisdom :)

Consider the following two approaches to creating an object of counts from an array of filters and a collection of items (structure is irrelevant to the question):

Using reduce

const filterFields= ['filter1', 'filter2']
filterCounts = filterFields.reduce((filterCountsAccumulator, currentFilterField) => {
  filterCountsAccumulator[currentFilterField] = getCounts(items, currentFilterField)
  return filterCountsAccumulator
}, {})

Using forEach + object assignment

const filterFields= ['filter1', 'filter2']
filterCounts = {}
filterFields.forEach(currentFilterField => {
  filterCounts[currentFilterField] = getCounts(items, currentFilterField)
})

I like the elegance of reduce but find the forEach approach much more readable as it more clearly shows the structure of the resulting filterCounts object.

Is it just my inexperience with reduce, or would you agree that forEach communicates intent more clearly in this case?

Are there other reasons to prefer one approach over the other?

Many thanks in advance :)

DEV Community: phivk

considering reduce vs forEach + object assignment