Playing with arrays

Check if all array elements are equals

arr = [0, 0, 0, 0, 0, 0, 0]
puts true if arr.uniq.length == 1

Array includes a sub array

(subarray & array) == array

Compute values occurences

[1, 1, 2, 3, 4, 5, 5, 5, 5].tally
=> {1=>2, 2=>1, 3=>1, 4=>1, 5=>4}