How To Convert An Array Of Hashes Into A Hash in Ruby

To convert:

arr = [{a: 1}, {b: 2}, {c: 3}]

into:

h = { a: 1, b: 2, c: 3 }

Method 1: Use the reduce method

Use the reduce method along with the merge method:

arr = [{a: 1}, {b: 2}, {c: 3}]
arr.reduce({}, :merge)

| :a=>1 | :b=>2 | :c=>3 |

Method 2: Use the inject method

Use the inject method along with the merge method:

arr = [{a: 1}, {b: 2}, {c: 3}]
arr.inject(:merge)

| :a=>1 | :b=>2 | :c=>3 |

Hash#merge creates a new hash on each iteration. For bigger arrays, it is more performant to use Hash#merge!/Hash#update.