How to count duplicates in Ruby Arrays

Question

How do you count duplicates in a ruby array?

For example, if my array had three a\'s, how could I count that

Answer 1

I've used reduce/inject for this in the past, like the following

array = [1,5,4,3,1,5,6,8,8,8,9]
array.reduce (Hash.new(0)) {|counts, el| counts[el]+=1; counts}

produces

=> {1=>2, 5=>2, 4=>1, 3=>1, 6=>1, 8=>3, 9=>1}