On Rails, is there a shortcut to check for boolean defined variable and use its value or use a default if not defined?

Question

On Ruby on Rails 3, I am trying to use the value of a boolean variable, if defined, otherwise use default value true. How should I write something like this?

if var.defined?
  var 
else
 true
end

Thanks in advance

Answer 1

You can do:

aVar ||= aVar.nil?

Which will assign the value true if the variable doesn't already have a value.

The ||= operator assigns the right value to the left variable if the left variable doesn't have a value. It's great for assigning default values to variables. The aVar.nil? returns true if aVar doesn't exist or has a nil value. All together it achieves what you were looking to do.