Get array of values from array of hashes

Question

I have a array like this

arr = [{:id=>1}, {:id=>2}, {:id=>3}, {:id=>4}, {:id=>5}, {:id=>6}, {:id=>7}, {:id=>8}]

The result should be

result = [1, 2, 3, 4, 5, 6, 7, 8]

I used arr.map { |i| i.values } arr.map { |i| i.values } .However, the result is [[1], [2], [3], [4], [5], [6], [7], [8]] . Please help.

Answer 1

You should flatten the result, to get your desired output :

arr.flat_map { |i| i.values }

Read flat_map .

I don't know actual intention of yours, still if you want to collect all ids , you can write :

arr.collect { |h| h[:id] }

Answer 2

use flatten For return an one-dimensional a new array that is a one-dimensional flattening of this array (recursively)

 arr.map {|i| i.values}.flatten

Or simply map all ids

arr.collect {|i| i[:id]}