The best way I can describe what I'm looking for is to show you the failed code I've tried thus far:
case car
when ['honda', 'acura'].include?(car)
# code
when 'toyota' || 'lexus'
# code
end
I've got about 4 or 5 different when
situations that should be triggered by approximately 50 different possible values of car
. Is there a way to do this with case
blocks or should I try a massive if
block?
This question is related to
ruby-on-rails
ruby
syntax
switch-statement
You might take advantage of ruby's "splat" or flattening syntax.
This makes overgrown when
clauses — you have about 10 values to test per branch if I understand correctly — a little more readable in my opinion. Additionally, you can modify the values to test at runtime. For example:
honda = ['honda', 'acura', 'civic', 'element', 'fit', ...]
toyota = ['toyota', 'lexus', 'tercel', 'rx', 'yaris', ...]
...
if include_concept_cars
honda += ['ev-ster', 'concept c', 'concept s', ...]
...
end
case car
when *toyota
# Do something for Toyota cars
when *honda
# Do something for Honda cars
...
end
Another common approach would be to use a hash as a dispatch table, with keys for each value of car
and values that are some callable object encapsulating the code you wish to execute.
Another nice way to put your logic in data is something like this:
# Initialization.
CAR_TYPES = {
foo_type: ['honda', 'acura', 'mercedes'],
bar_type: ['toyota', 'lexus']
# More...
}
@type_for_name = {}
CAR_TYPES.each { |type, names| names.each { |name| @type_for_name[type] = name } }
case @type_for_name[car]
when :foo_type
# do foo things
when :bar_type
# do bar things
end
Source: Stackoverflow.com