hashwithindifferentaccess ruby
The "HashWithIndifferentAccess" class in Ruby is a utility class that allows you to access hash keys using either strings or symbols interchangeably. It is commonly used in Rails applications to handle incoming parameters and convert them into a hash that can be accessed in a consistent manner.
Here is an example of how to use HashWithIndifferentAccess in Ruby:
- First, you need to require the 'active_support' gem, which provides the implementation for HashWithIndifferentAccess:
require 'active_support/hash_with_indifferent_access'
- Next, you can create a new instance of HashWithIndifferentAccess:
params = HashWithIndifferentAccess.new
- You can then add key-value pairs to the hash using either strings or symbols as keys:
params[:name] = 'John'
params['age'] = 25
- You can access the values in the hash using either strings or symbols:
puts params[:name] # Output: John
puts params['age'] # Output: 25
- You can also use methods like
fetch
orslice
on the hash:
puts params.fetch(:name) # Output: John
puts params.slice(:name) # Output: { :name => 'John' }
- The HashWithIndifferentAccess class also provides methods like
delete
,merge
, andto_h
, which work similarly to regular hashes:
params.delete(:name)
puts params # Output: { 'age' => 25 }
new_params = params.merge({ :city => 'New York' })
puts new_params # Output: { 'age' => 25, :city => 'New York' }
hash = params.to_h
puts hash # Output: { 'age' => 25 }
That's a brief explanation of how to use the HashWithIndifferentAccess class in Ruby. It provides a convenient way to handle hash keys without worrying about whether they are strings or symbols.