How to sum the values ​​of multiple hashes in ruby?

Question

ruby

there is an array of several hashes (the number varies)
example

arr = [{name: 'd1', value: 10}, {name: 'd2', value: 30}, {name: 'd1', value: 5},  {name: 'd3', value:4}, {name: 'd2', value: 5}]

How to get an array from it with the sum of the same names
i.e. should be something like this

arr = [{name: 'd1', value: 15], {name: 'd2', value: 35}, {name: 'd3', value: 4}

Answer 1

arr
  .group_by{|n| n[:name]}
  .map{|n| { name: n[0], value: n[1].sum{|m| m[:value]} }}