CODEWITHSUNDEEP
ruby
The F
The F

Reputation: 3714

Select subset of list matching condition

Assume I am supposed to find the sum of multiples of 7 an 9 up to a limit of 255, this is what I do:

(0..255).select do |i|
  i % 7 == 0 || i % 9 == 0
end.inject(:+)

I would like to remove the magic numbers and have the method more versatile:

divisors = [7,9,13]

(0..255).select do |i|
  divisors.each do |d|
    i % d == 0
  end
end.inject(:+)

What is an idiomatic way of doing this?

Upvotes: 1

Views: 117

Answers (1)

Harsh Gupta
Harsh Gupta

Reputation: 4538

Use Array#map and Enumerable#any? 

divisables.map do |d|
  i % d == 0
end.any?

HTH

Edit: Alternatively, as @undur_gongor said, you can also use any? like

divisables.any? { |d| i % d == 0 }

Upvotes: 2

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