How to Convert Ruby Formatted JSON String to JSON Hash in Ruby

How to convert a ruby hash object to JSON?

One of the numerous niceties of Ruby is the possibility to extend existing classes with your own methods. That's called "class reopening" or monkey-patching (the meaning of the latter can vary, though).

So, take a look here:

car = {:make => "bmw", :year => "2003"}
# => {:make=>"bmw", :year=>"2003"}
car.to_json
# NoMethodError: undefined method `to_json' for {:make=>"bmw", :year=>"2003"}:Hash
#   from (irb):11
#   from /usr/bin/irb:12:in `<main>'
require 'json'
# => true
car.to_json
# => "{"make":"bmw","year":"2003"}"

As you can see, requiring json has magically brought method to_json to our Hash.

How to convert ruby formatted json string to json hash in ruby?

You can try eval method on temp json string

Example:

eval(temp)

This will return following hash

{"accept"=>"*/*", "host"=>"localhost:4567", "version"=>"HTTP/1.1", "user_agent"=>"curl/7.22.0 (x86_64-pc-linux-gnu) libcurl/7.22.0 OpenSSL/1.0.1 zlib/1.2.3.4 libidn/1.23 librtmp/2.3", "http_token"=>"375fe428b1d32787864264b830c54b97"}

Hope this will help.

Thanks

Convert JSON string to hash

It's most likely because this isn't valid JSON. Change your single quotes to double quotes, like so:

test = '[{"domain": "abc.com"}, {"domain": "def.com"}, {"domain": "ghi.com"}]'

An explanation can be found here, and you can validate your JSON here.

How to convert JSON to a Ruby hash

What about the following snippet?

require 'json'
value = '{"val":"test","val1":"test1","val2":"test2"}'
puts JSON.parse(value) # => {"val"=>"test","val1"=>"test1","val2"=>"test2"}

Parsing a JSON string in Ruby

This looks like JavaScript Object Notation (JSON). You can parse JSON that resides in some variable, e.g. json_string, like so:

require 'json'
JSON.parse(json_string)

If you’re using an older Ruby, you may need to install the json gem.

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There are also other implementations of JSON for Ruby that may fit some use-cases better:

• YAJL C Bindings for Ruby
• JSON::Stream

How can I convert a string in my JSON file into a Ruby hash?

I think something like this would help:

def media_url
  tweet = self.object
  JSON.parse(tweet.media[0].gsub('=>', ':'))["media_url"]
end

You need to replace => with : in order for JSON.parse to work

Or

To get the complete hash you can use a more generic method like media:

def media
  tweet = self.object
  JSON.parse(tweet.media[0].gsub('=>', ':'))
end

How to convert a hash to JSON without the converted string being full of backslashes

It seems like you are confused about the actual content of the string. The backslashes are part of the string representation, and are not actually in the string.

Take for example '"' a single character ". When you enter this into irb the output will be:

s = '"'
#=> "\""

From the result "\"" the starting " and ending " mark the begin and ending of the string while \" is an escaped double quote, and represents a single ". The reason this double quote is escaped is because you want Ruby to interpret it as an " character, not as the end of the string.

You can view the actual contents of the string without escape characters by printing it to the console.

puts s
# "
#=> nil

Here you can see that there is no backslash in the contents of the string.

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The same applies for your to_json call, which returns a string:

data = {"a" => "b", "c" => "d", "e" => "f"}
json = data.to_json
#=> "{\"a\":\"b\",\"c\":\"d\",\"e\":\"f\"}"
puts json
# {"a":"b","c":"d","e":"f"}
#=> nil

Like you can see there are no backslashes in the contents of the string, only in the string representation.

How to turn into a hash what has been made into a string of a hash?

str = "{ H: 50, Q: 25, D: 10, N: 5, P: 1 }"

str.gsub(/(\S+): +(\d+)/).with_object({}) { |_,h| h[$1.to_sym] = $2.to_i }
  #=> {:H=>50, :Q=>25, :D=>10, :N=>5, :P=>1}

This employs the form of String#gsub that takes an argument and no block, returning an enumerator that can be chained to Enumerator#with_object. This form of gsub merely generates matches; it makes no substitutions.

One advantage of this construct is that it avoids the creation of temporary arrays.

The regular expression can be written in free-spacing mode to make it self-documenting.

/
(\S+)  # match 1+ characters other than whitespaces, save to capture group 1 
:[ ]+  # match ':' followed by 1+ spaces
(\d+)  # match 1+ digits, save to capture group 2
/x     # free-spacing regex definition mode

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