What is the easiest way to extract data from a JSON string in Ruby?

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1

What is the easiest way to extract data from a JSON string in Ruby?

I have the following JSON string:

string = '{"desc":{"someKey":"someValue","anotherKey":"value"},"main_item":{"stats":{"a":8,"b":12,"c":10}}}'

How can I efficiently parse JSON in Ruby to access its data? Is there a built-in method for Ruby JSON parse operations?

2

Been working with Ruby for years, and honestly, ruby json parse makes it super simple to handle JSON data. Just require the built-in json module and use JSON.parse to convert a string into a Ruby hash.

require 'json'

string = '{"desc":{"someKey":"someValue","anotherKey":"value"},"main_item":{"stats":{"a":8,"b":12,"c":10}}}'

data = JSON.parse(string)

puts data["desc"]["someKey"]  # Output: someValue
puts data["main_item"]["stats"]["b"]  # Output: 12

Once parsed, you can access JSON data just like any other Ruby hash. Clean and simple!

3

Great approach! But one small tweak can make it even better—if you prefer using symbols instead of strings for keys, add symbolize_names: true. This keeps things efficient and avoids unnecessary string allocations in ruby json parse.

data = JSON.parse(string, symbolize_names: true)

puts data[:desc][:someKey]  # Output: someValue
puts data[:main_item][:stats][:b]  # Output: 12

Symbols are immutable, so they won’t create new objects every time you access a key. Cleaner, faster, and more Ruby-like!

4

Both methods are solid, but let’s make sure we handle errors properly. JSON from external sources can be unpredictable, so wrapping ruby json parse in a begin-rescue block prevents unexpected crashes.

begin
  data = JSON.parse(string, symbolize_names: true)
  puts data.dig(:desc, :someKey) # Using dig to safely access nested keys
rescue JSON::ParserError => e
  puts "Invalid JSON format: #{e.message}"
end

dig is useful when accessing deeply nested keys—it prevents nil errors if a key is missing. And always rescue JSON::ParserError to keep your app from breaking on bad JSON!