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Ruby Hash.dig() Method

By IncludeHelp Last updated : December 01, 2024

In this article, we will study about Hash.dig() Method. The working of this method can be predicted with the help of its name but it is not as simple as it seems. Well, we will understand this method with the help of its syntax and program code in the rest of the content.

Description and Usage

This method is a public instance method that is defined in the ruby library especially for Hash class. This method works in a way that takes out the nested value stored after a sequence of key objects. dig method is invoked at every step of the traverse. 'nil' is returned when no value is found at any specific step.

Syntax

Hash_object.dig(obj, ...)

Parameters

You can pass any number of arguments inside this method. However, at least one argument is mandatory.

Example 1

=begin
  Ruby program to demonstrate dig method
=end  

hsh = {country:{state:{city:"Haridwar"}}}

puts "Hash dig implementation"

if(hsh.dig(:country,:state,:city))
  puts "The value is #{hsh.dig(:country,:state,:city)}"
else
  puts "Value not available"
end

Output

Hash dig implementation
The value is Haridwar

Explanation

In the above code, you can observe that we are digging some value from the hash object. We have passed three arguments inside the dig method namely country, state, and city. The method has traversed the hash object until it does not find the value. The method must have returned 'nil' if no value is found inside the hash object during the process of digging.

Example 2

=begin
  Ruby program to demonstrate dig method
=end

hsh = { foo: [10, 11, 12] }

puts "Hash dig implementation"

puts hsh.dig(:foo, 1)              
puts hsh.dig(:foo, 1, 0)           
puts hsh.dig(:foo, :bar)     

Output

Hash dig implementation
11
Integer does not have #dig method
(repl):10:in `dig'
(repl):10:in `<main>'

Explanation

In the above code, you can observe that we are digging value from the hash object which has a key and whose value is an integer array. You can utmost one value along with one key in case of the value of array type.