Ruby Deep Merge

Ruby Deep Merge is a method that allows merging two hashes into one hash. It is a powerful feature that is used when you have nested hashes or arrays. With Ruby Deep Merge, you can easily merge two or more hashes together without the need of writing any custom code.

Usage

To use the Ruby Deep Merge method, you need to include the ActiveSupport library in your code. You can do this by adding the following to your Gemfile:

gem 'activesupport'

Once you have included the ActiveSupport library, you can use the deep_merge method on any two hashes. Here is an example:

require 'active_support/core_ext/hash/deep_merge'

hash1 = {one: 1, two: 2}
hash2 = {two: 'two', three: 3}

merged_hash = hash1.deep_merge(hash2)
puts merged_hash.inspect
# => {:one=>1, :two=>"two", :three=>3}

In the above example, hash1 and hash2 are two hashes that we want to merge. The deep_merge method is called on hash1 and it accepts hash2 as an argument. The result is a new hash that contains the merged data from both hashes.

Handling Conflicts

When you merge two hashes, there could be conflicts if both hashes have the same key. In such cases, you can specify how the conflicts should be resolved. Here is an example:

require 'active_support/core_ext/hash/deep_merge'

hash1 = {one: 1, two: {three: 3}}
hash2 = {two: {four: 4}, three: 3}

merged_hash = hash1.deep_merge(hash2) {|key, val1, val2| val1.merge(val2)}
puts merged_hash.inspect
# => {:one=>1, :two=>{:three=>3, :four=>4}, :three=>3}

In the above example, there is a conflict when merging the two key. To resolve the conflict, we pass a block to the deep_merge method. This block is called when there is a conflict and it takes three arguments:

• key - The key that is being merged.
• val1 - The value of the key in the first hash.
• val2 - The value of the key in the second hash.

In the example, we are merging the values of the two key by calling the merge method on val1 and val2.

Conclusion

Ruby Deep Merge is a powerful feature that allows merging two or more hashes together. It is especially useful when you have nested hashes or arrays. With the deep_merge method, you can easily merge hashes together without the need of writing any custom code.