How do I test if all items in an array are identical?
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) 开发者_开发问答[3,3,3,3,3]
or ["rabbits","rabbits","rabbits"]
but will return false with [1,2,3,4,5]
or ["rabbits","rabbits","hares"]
.
Thanks
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.)
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.
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
I would use:
array = ["rabbits","rabbits","hares", nil, nil]
array.uniq.compact.length == 1
I used to use:
array.reduce { |x,y| x == y ? x : nil }
It may fail when array
contains nil
.
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