Here’s a method I encountered recently at my work and I found it might be useful to you as well.
There might be some attribute which you want to set to a default parameter if the user didn’t supply any, eg:
# if the parameters is nil or blank, we will default to french fries
sides = params[:sides].present? ? params[:sides] : "french fries"
This one liner looks concise, but we can make it even shorter like this :
sides = params[:sides].presence || "french fries"
The presence method will return nil if the string is a blank string / empty array or nil , then the || (double pipe) will use the value on the right side (“french fries”).
''.presence
# => nil
If the string is not blank, .presence will return the string itself.
When params[:sides] == “” :
sides = params[:sides].presence || "french fries"
# => "french fries"
When params[:sides] == “corn” ,
sides = params[:sides].presence || "french fries"
# => "corn"
Documentation : http://api.rubyonrails.org/classes/Object.html#method-i-presence