Ruby なら、こういう感じ

members = [ {id: 1, age: 30}, {id: 2, age: 20}, {id: 3, age: 50} ]

p members.sort_by{ |member| member[ :age ] }

出力
[{:id=>2, :age=>20}, {:id=>1, :age=>30}, {:id=>3, :age=>50}]