How do I test if all items in an array are identical?

Question

I can generate a few lines of code that will do this but I'm wondering if there's a nice clean Rubyesque way of doing this. In case I haven't been clear, what I'm looking for is an array method that will return true if given (say) [3,3,3,3,3] or ["rabbits","rabbits","rabbits"] but will return false with [1,2,3,4,5] or ["rabbits","rabbits","hares"].

Thanks

Answer 1

You can use Enumerable#all? which returns true if the given block returns true for all the elements in the collection.

array.all? {|x| x == array[0]}

(If the array is empty, the block is never called, so doing array[0] is safe.)

Answer 2

class Array
  def same_values?
    self.uniq.length == 1
  end
end


[1, 1, 1, 1].same_values?
[1, 2, 3, 4].same_values?

What about this one? It returns false for an empty array though, you can change it to <= 1 and it will return true in that case. Depending on what you need.

Answer 3

I too like preferred answer best, short and sweet. If all elements were from the same Enumerable class, such as Numeric or String, one could use

def all_equal?(array) array.max == array.min end