Ruby array repeat value if next not present,

Question

How can we achieve this in Ruby?

xs = [1,2,3]
x = 5

Then I need that sum = 1+2+3+1+2 = 9

Answer 1

You have the abstractions you need in the core, just wire them together: Enumerable#cycle, Enumerable#take and Enumerable#inject:

>> [1, 2, 3].cycle.take(5).inject(0, :+)
=> 9

That's the functional/declarative approach: use abstractions (either existing or those you implement yourself) so you can write code that describes what you are doing instead of how you are doing it.