Sum the value of array in hash

Question

This is my array

[{:amount=>10, :gl_acct_id=>1, :alt_amount=>20}, {:amount=>20, :gl_acct_id=>2 , :alt_amount=>30}] 

i want result

[{:amount => 30}] or {:amount = 30} 

Any idea?

Answer 1

Ruby versions >= 2.4.0 has an Enumerable#sum method. So you can do

arr.sum {|h| h[:amount] } 

Answer 2

array.map { |h| h[:amount] }.sum