I face a weirb problem with optionals parameters in ruby. This is my code :
def foo options={:test => true} puts options[:test] end foo # => puts true foo :lol => 42 # => puts nil I can not figure out why the second call puts nil. Is seems that putting an other parameter set :test to nil.
Thanks.
It happens because if it is a default parameter, passing a hash parameter will completely overwrite it (ie. it sets options = {:lol => 42}), so the options[:test] key no longer exists.
To give particular hash keys default values, try:
def foo options={} options = {:test => true}.merge options puts options[:test] end In this case, we merge a hash with default values for certain keys ({:test => true}), with another hash (containing the key=>values in the argument). If a key occurs in both hash objects, the value in the hash passed to the merge function will take precedence.
