[ruby-on-rails] How to convert a ruby hash object to JSON?

How to convert a ruby hash object to JSON? So I am trying this example below & it doesn't work?

I was looking at the RubyDoc and obviously Hash object doesn't have a to_json method. But I am reading on blogs that Rails supports active_record.to_json and also supports hash#to_json. I can understand ActiveRecord is a Rails object, but Hash is not native to Rails, it's a pure Ruby object. So in Rails you can do a hash.to_json, but not in pure Ruby??

car = {:make => "bmw", :year => "2003"}
car.to_json

require 'json/ext' # to use the C based extension instead of json/pure

puts {hash: 123}.to_json

You should include json in your file

For Example,

require 'json'

your_hash = {one: "1", two: "2"}
your_hash.to_json

For more knowledge about json you can visit below link. Json Learning

You can also use JSON.generate:

require 'json'

JSON.generate({ foo: "bar" })
=> "{\"foo\":\"bar\"}"

Or its alias, JSON.unparse:

require 'json'

JSON.unparse({ foo: "bar" })
=> "{\"foo\":\"bar\"}"

Add the following line on the top of your file

require 'json'

Then you can use:

car = {:make => "bmw", :year => "2003"}
car.to_json

Alternatively, you can use:

JSON.generate({:make => "bmw", :year => "2003"})