Ruby Methods and Optional parameters

Question

I\'m playing with Ruby on Rails and I\'m trying to create a method with optional parameters. Apparently there are many ways to do it. I trying naming the optional parameters

Answer 1

The problem is the default value of options is the entire Hash in the second version you posted. So, the default value, the entire Hash, gets overridden. That's why passing nothing works, because this activates the default value which is the Hash and entering all of them also works, because it is overwriting the default value with a Hash of identical keys.

I highly suggest using an Array to capture all additional objects that are at the end of your method call.

def my_info(name, *args)
  options = args.extract_options!
  age = options[:age] || 27
end

I learned this trick from reading through the source for Rails. However, note that this only works if you include ActiveSupport. Or, if you don't want the overhead of the entire ActiveSupport gem, just use the two methods added to Hash and Array that make this possible.

rails / activesupport / lib / active_support / core_ext / array / extract_options.rb

So when you call your method, call it much like you would any other Rails helper method with additional options.

my_info "Ned Stark", "Winter is coming", :city => "Winterfell"