We can sort ruby hash by two keys like below.
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array.sort!{|a, b| a[:value_1] <=> b[:value_1] || a[:value_2] <=> b[:value_2] } |
Well, how we can sort by three keys?
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array.sort{|a, b| a[:value_1] <=> b[:value_1] || a[:value_2] <=> a[:value_2] || a[:value_3] <=> b[:value_3] } |
So, how about make function to sort hash?
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# @param [Array] array the hash array which you want to compare elements # @param [Array] value_names value name to compare, like [:value_1, :value_2, ...] # @param [Array] orders compare order. To compare order like SQL # 'order by value_1 desc, value_2 asc' then [-1, 1] def multicompare(a, b, value_names, orders) if value_names.length == 0 return 0 else value_name = value_names[0] return (orders[0] * (a[value_name] <=> b[:value_name])) || multicompare(a, b, value_names[1..-1], orders[1..-1]) end end array.sort{|a, b| multicompare(a, b, [:value_1, :value_2, :value_3], [1, -1, 1]) } |
