How to merge Ruby hashes

Question

How can I merge these two hashes:

{:car => {:color => \"red\"}}
{:car => {:speed => \"100mph\"}}

To get:

{:car          


        

Answer 1

You can use the merge method defined in the ruby library. https://ruby-doc.org/core-2.2.0/Hash.html#method-i-merge

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Example

h1={"a"=>1,"b"=>2} 
h2={"b"=>3,"c"=>3} 
h1.merge!(h2)

It will give you output like this {"a"=>1,"b"=>3,"c"=>3}

Merge method does not allow duplicate key, so key b will be overwritten from 2 to 3.

To overcome the above problem, you can hack merge method like this.

h1.merge(h2){|k,v1,v2|[v1,v2]}

The above code snippet will be give you output

{"a"=>1,"b"=>[2,3],"c"=>3}