I usually do
value = input || "default"
so if input = nil
value = "default"
But how can I do this so instead of nil It also counts an empty string '' as nil
I want so that if I do
input = ''
value = input || "default"
=> "default"
Is there a simple elegant way to do this without if?
Rails adds presence method to all object that does exactly what you want
input = ''
value = input.presence || "default"
=> "default"
input = 'value'
value = input.presence || "default"
=> "value"
input = nil
value = input.presence || "default"
=> "default"
blank?I usually do in this way:
value = input.blank? ? "default" : input
In response to the case that input might not be defined, you may guard it by:
value = input || (input.blank? ? "default" : input)
# I just tried that the parentheses are required, or else its return is incorrect
For pure ruby (not depending on Rails), you may use empty? like this:
value = input || (input.empty? ? "default" : input)
or like this (thanks @substantial for providing this):
value = (input ||= "").empty? ? "default" : input
undefined input.
value = (input ||= "").blank? ? "default" : input This will set input to an empty string if undefined.Object class to include blank? just like Rails does. Ask a new question if you need further help.Maybe irrelavant but I would use highline like this:
require "highline/import"
input = ask('Input: ') { |q| q.default = "default" }
It works without Rails. Really neat solution.
ruby-on-rails, hence the Rails specific answers.