Equivalent of .try() for a hash to avoid “undefined method” errors on nil? [duplicate]

Answer 1

When you do this:

myhash[:one][:two][:three]

You're just chaining a bunch of calls to a "[]" method, an the error occurs if myhash[:one] returns nil, because nil doesn't have a [] method. So, one simple and rather hacky way is to add a [] method to Niclass, which returns nil: i would set this up in a rails app as follows:

Add the method:

#in lib/ruby_extensions.rb
class NilClass
  def [](*args)
    nil
  end
end

Require the file:

#in config/initializers/app_environment.rb
require 'ruby_extensions'

Now you can call nested hashes without fear: i'm demonstrating in the console here:

>> hash = {:foo => "bar"}
=> {:foo=>"bar"}
>> hash[:foo]
=> "bar"
>> hash[:doo]
=> nil
>> hash[:doo][:too]
=> nil