%w(a b c a c d).uniq
count_hash = {}
%w(a b c a c d).each do |item|
key = item.to_sym
if count = count_hash[key]
count_hash[key] = count + 1
else
count_hash[key] = 1
end
end
数组是
array = [[1],[2],[3],[0],[1,2],[1,0],[0,1]]
希望排序整个数组,先按照数组 元素个数 ,如果个数相同再 按照首个元素大小 。
array.sort_by {|a| [a.size, a[0]] }