How to Check if a Value Exists in a Set of Nested Hashes in Ruby


This coding exercise extends our knowledge on the Hash data structure and walks through how to check and see if a value exists in any number of Hash collections nested inside an array.


Build a method that looks through an array of hashes to see if a value exists anywhere inside of one of the hashes.

Exercise File

Code File

Exercise Description

In order to properly pass this coding exercise you’ll need to open up Ruby’s Array class and add a method called value_included?that iterates through the array of hashes and returns true if a value exists inside any of the hash values and false if the value is not found.

Example Data

books = [
    :title => 'Fountainhead',
    :author => 'Ayn Rand'
    :title => 'Deep Work',
    :author => 'Cal Newport'

Example Process

books.value_included? 'Deep Work' # true
books.value_included? 'Something that does not exist' # false

Real World Usage

This exercise shows you how to work with nested collections. This is particularly useful when working with API data that includes nested data that needs to be accessed.


Can be found on the solutions branch on github.


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