Ruby: merge nested hash

ruby hash merge nested
user1223862 picture user1223862 · Feb 21, 2012 · Viewed 39.7k times · Source

I would like to merge a nested hash.

a = {:book=>
    [{:title=>"Hamlet",
      :author=>"William Shakespeare"
      }]}

b = {:book=>
    [{:title=>"Pride and Prejudice",
      :author=>"Jane Austen"
      }]}

I would like the merge to be:

{:book=>
   [{:title=>"Hamlet",
      :author=>"William Shakespeare"},
    {:title=>"Pride and Prejudice",
      :author=>"Jane Austen"}]}

What is the nest way to accomplish this?

Answer

xlembouras picture xlembouras · Sep 25, 2012

For rails 3.0.0+ or higher version there is the deep_merge function for ActiveSupport that does exactly what you ask for.

Related questions

How to add new item to hash

I'm new to Ruby and don't know how to add new item to already existing hash. For example, first I construct hash: hash = {item1: 1} after that a want to add item2 so after this I have hash like this: {item1: 1, …

Read More
How to get a specific output iterating a hash in Ruby?

I want to get a specific output iterating a Ruby Hash. This is the Hash I want to iterate over: hash = { 1 => ['a', 'b'], 2 => ['c'], 3 => ['d', 'e', 'f', 'g'], 4 => ['h'] } This is the output I would like …

Read More
How to add to an existing hash in Ruby

In regards to adding an key => value pair to an existing populated hash in Ruby, I'm in the process of working through Apress' Beginning Ruby and have just finished the hashes chapter. I am trying to find the simplest …

Read More