CODEWITHSUNDEEP
arraysruby
NothingToSeeHere
NothingToSeeHere

Reputation: 2363

Finding blank arrays within ruby arrays Rails 4

I am trying build a sentence out of 3 arrays with the count of each array.

cats = Cat.all 
dogs = Dog.all
birds = Bird.all 

animals = ["#{cats.count} Cats", "#{dogs.count} Dogs", "#{birds.count} Birds"]

sentence = animals.each.map{ |r| r  }.join(",  ")

Right now, this works, but if I have no cats sentence outputs to 

"O Cats, 5 Dogs, 4 Birds"

and I'ld like it to just say:

"5 Dogs & 4 Birds"

or, at the very least:

"5 Dogs, 4 Birds"

I feel like I might need to use an array of hashes, but I'm a bit lost.

Upvotes: 0

Views: 51

Answers (2)

Aetherus
Aetherus

Reputation: 8888

Yes, you need a hash.

cats = Cat.all 
dogs = Dog.all
birds = Bird.all

animals = {
  cats: cats.count,
  dogs: dogs.count,
  birds: birds.count
}

sentence = animals.reject{|k, v| v.zero?}
                  .map{|k, v| "#{v} #{k.to_s.capitalize}"}
                  .join(', ')

My suggestion: keep data as data till the last moment, so that you can have maximum flexibility to display it in various ways. I feel that the animals in your code thinks rendering too soon.

Upvotes: 3

davidhu
davidhu

Reputation: 10434

To get "5 Dogs, 4 Birds", you can do

sentence = animals.each.map{ |r| /^0\s/.match(r) ? nil : r  }.compact.join(", ")

The regex matches anything that starts with 0 and a space. If there is a match, return nil, or return the original string. The compact method removes nil elements from the array, and finally you join the elements.

If you want 5 Dogs & 4 Birds, you can define a method that performs that function.

def english_join(array)
  return array.to_s if array.nil? or array.length <= 1
  array[0..-2].join(", ") + " & " + array[-1]
end

Then you can do 

sentence = english_join(animals.each.map{ |r| /^0\s/.match(r) ? nil : r  }.compact)

If you have 0 cats, 5 dogs, and 4 birds, this returns 5 Dogs & 4 Birds.

If you have 2 cats, 5 dogs, and 4 birds, this returns 2 Cats, 5 Dogs & 4 Birds

Upvotes: 2

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