Selecting the highest value in attribute from hash of arrays












2















I have this hash:



h = {

  124 => ["shoes", "59.99"],

  456 => ["pants", "49.50"],

  352 => ["socks", "3.99"]

}


Each value has two elements. They are a name (e.g., "shoes", "pants", "socks") and a price (e.g., "59.99", "49.50", and "3.99"). I need to select the value that has the highest price. That would be key 124 with price "59.99". How do I select the hash with the highest price?



I tried this:



h.select{ |x| x[1] }.max

#=> [456, ["pants", "49.50"]]


But this gives me the max value and returns the key 456.






arrays ruby hash







share|improve this question





























    2















    I have this hash:



    h = {
    
  124 => ["shoes", "59.99"],
    
  456 => ["pants", "49.50"],
    
  352 => ["socks", "3.99"]
    
}


    Each value has two elements. They are a name (e.g., "shoes", "pants", "socks") and a price (e.g., "59.99", "49.50", and "3.99"). I need to select the value that has the highest price. That would be key 124 with price "59.99". How do I select the hash with the highest price?



    I tried this:



    h.select{ |x| x[1] }.max
    
#=> [456, ["pants", "49.50"]]


    But this gives me the max value and returns the key 456.






    arrays ruby hash







    share|improve this question



























      2












      2








      2








      I have this hash:



      h = {
      
  124 => ["shoes", "59.99"],
      
  456 => ["pants", "49.50"],
      
  352 => ["socks", "3.99"]
      
}


      Each value has two elements. They are a name (e.g., "shoes", "pants", "socks") and a price (e.g., "59.99", "49.50", and "3.99"). I need to select the value that has the highest price. That would be key 124 with price "59.99". How do I select the hash with the highest price?



      I tried this:



      h.select{ |x| x[1] }.max
      
#=> [456, ["pants", "49.50"]]


      But this gives me the max value and returns the key 456.






      arrays ruby hash







      share|improve this question
















      I have this hash:



      h = {
      
  124 => ["shoes", "59.99"],
      
  456 => ["pants", "49.50"],
      
  352 => ["socks", "3.99"]
      
}


      Each value has two elements. They are a name (e.g., "shoes", "pants", "socks") and a price (e.g., "59.99", "49.50", and "3.99"). I need to select the value that has the highest price. That would be key 124 with price "59.99". How do I select the hash with the highest price?



      I tried this:



      h.select{ |x| x[1] }.max
      
#=> [456, ["pants", "49.50"]]


      But this gives me the max value and returns the key 456.






      arrays ruby hash




      arrays ruby hash






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Nov 21 '18 at 7:45









      Stefan

      75.4k894142




      75.4k894142










      asked Nov 20 '18 at 21:49









      Tobyrrr00Tobyrrr00

      192




      192
























          4 Answers
          4






          active

          oldest

          votes


















          6














          The most idiomatic would probably be this:



          h.max_by { |_, v| v.last.to_f }
          
#=> [124, ["shoes", "59.99"]]





          share|improve this answer


























          • I suggest you show the return value: #=> [124, ["shoes", "59.99"]].

            – Cary Swoveland
            Nov 21 '18 at 2:39



















          5














          You can dig into the structure using parentheses like this:



          h = {
          
  124 => ["shoes", "59.99"],
          
  456 => ["pants", "49.50"],
          
  352 => ["socks", "3.99"]
          
}
          

          
h.max_by{|_, (_, price)| price.to_f}
          
# => [124, ["shoes", "59.99"]]





          share|improve this answer































            3














            You can first sort the hash:



            sorted = hash.sort_by { |key, value| value[1].to_f }
            
# => [[352, ["socks", "3.99"]], [456, ["pants", "49.50"]], [124, ["shoes", "59.99"]]]


            And then you can select the last pair:



            sorted[-1]
            
# => [124, ["shoes", "59.99"]]





            share|improve this answer





















            • 6





              Or using max_by, hash.max_by { |k,v| v.last.to_f }

              – Marcin Kołodziej
              Nov 20 '18 at 22:04













            • Thank you guys. You're a lifesaver.

              – Tobyrrr00
              Nov 20 '18 at 22:28






            • 1





              You are sorting the values alphabetically, not by their numerical value.

              – Stefan
              Nov 21 '18 at 7:42



















            1














            If you don’t mind the keys, another option could be:



            h.values.map(&:reverse).max



            #=> ["59.99", "shoes"]






            share|improve this answer
























            • Notice that this compares the prices as strings, not as floats, and it is not certain whether the OP wanted that.

              – sawa
              Nov 21 '18 at 3:12











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            4 Answers
            4






            active

            oldest

            votes








            4 Answers
            4






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            6














            The most idiomatic would probably be this:



            h.max_by { |_, v| v.last.to_f }
            
#=> [124, ["shoes", "59.99"]]





            share|improve this answer


























            • I suggest you show the return value: #=> [124, ["shoes", "59.99"]].

              – Cary Swoveland
              Nov 21 '18 at 2:39
















            6














            The most idiomatic would probably be this:



            h.max_by { |_, v| v.last.to_f }
            
#=> [124, ["shoes", "59.99"]]





            share|improve this answer


























            • I suggest you show the return value: #=> [124, ["shoes", "59.99"]].

              – Cary Swoveland
              Nov 21 '18 at 2:39














            6












            6








            6







            The most idiomatic would probably be this:



            h.max_by { |_, v| v.last.to_f }
            
#=> [124, ["shoes", "59.99"]]





            share|improve this answer















            The most idiomatic would probably be this:



            h.max_by { |_, v| v.last.to_f }
            
#=> [124, ["shoes", "59.99"]]






            share|improve this answer














            share|improve this answer



            share|improve this answer








            edited Nov 21 '18 at 7:46









            Stefan

            75.4k894142




            75.4k894142










            answered Nov 21 '18 at 1:24









            Michael KohlMichael Kohl

            57.2k10112138




            57.2k10112138













            • I suggest you show the return value: #=> [124, ["shoes", "59.99"]].

              – Cary Swoveland
              Nov 21 '18 at 2:39



















            • I suggest you show the return value: #=> [124, ["shoes", "59.99"]].

              – Cary Swoveland
              Nov 21 '18 at 2:39

















            I suggest you show the return value: #=> [124, ["shoes", "59.99"]].

            – Cary Swoveland
            Nov 21 '18 at 2:39





            I suggest you show the return value: #=> [124, ["shoes", "59.99"]].

            – Cary Swoveland
            Nov 21 '18 at 2:39













            5














            You can dig into the structure using parentheses like this:



            h = {
            
  124 => ["shoes", "59.99"],
            
  456 => ["pants", "49.50"],
            
  352 => ["socks", "3.99"]
            
}
            

            
h.max_by{|_, (_, price)| price.to_f}
            
# => [124, ["shoes", "59.99"]]





            share|improve this answer




























              5














              You can dig into the structure using parentheses like this:



              h = {
              
  124 => ["shoes", "59.99"],
              
  456 => ["pants", "49.50"],
              
  352 => ["socks", "3.99"]
              
}
              

              
h.max_by{|_, (_, price)| price.to_f}
              
# => [124, ["shoes", "59.99"]]





              share|improve this answer


























                5












                5








                5







                You can dig into the structure using parentheses like this:



                h = {
                
  124 => ["shoes", "59.99"],
                
  456 => ["pants", "49.50"],
                
  352 => ["socks", "3.99"]
                
}
                

                
h.max_by{|_, (_, price)| price.to_f}
                
# => [124, ["shoes", "59.99"]]





                share|improve this answer













                You can dig into the structure using parentheses like this:



                h = {
                
  124 => ["shoes", "59.99"],
                
  456 => ["pants", "49.50"],
                
  352 => ["socks", "3.99"]
                
}
                

                
h.max_by{|_, (_, price)| price.to_f}
                
# => [124, ["shoes", "59.99"]]






                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Nov 21 '18 at 2:47









                sawasawa

                130k29201301




                130k29201301























                    3














                    You can first sort the hash:



                    sorted = hash.sort_by { |key, value| value[1].to_f }
                    
# => [[352, ["socks", "3.99"]], [456, ["pants", "49.50"]], [124, ["shoes", "59.99"]]]


                    And then you can select the last pair:



                    sorted[-1]
                    
# => [124, ["shoes", "59.99"]]





                    share|improve this answer





















                    • 6





                      Or using max_by, hash.max_by { |k,v| v.last.to_f }

                      – Marcin Kołodziej
                      Nov 20 '18 at 22:04













                    • Thank you guys. You're a lifesaver.

                      – Tobyrrr00
                      Nov 20 '18 at 22:28






                    • 1





                      You are sorting the values alphabetically, not by their numerical value.

                      – Stefan
                      Nov 21 '18 at 7:42
















                    3














                    You can first sort the hash:



                    sorted = hash.sort_by { |key, value| value[1].to_f }
                    
# => [[352, ["socks", "3.99"]], [456, ["pants", "49.50"]], [124, ["shoes", "59.99"]]]


                    And then you can select the last pair:



                    sorted[-1]
                    
# => [124, ["shoes", "59.99"]]





                    share|improve this answer





















                    • 6





                      Or using max_by, hash.max_by { |k,v| v.last.to_f }

                      – Marcin Kołodziej
                      Nov 20 '18 at 22:04













                    • Thank you guys. You're a lifesaver.

                      – Tobyrrr00
                      Nov 20 '18 at 22:28






                    • 1





                      You are sorting the values alphabetically, not by their numerical value.

                      – Stefan
                      Nov 21 '18 at 7:42














                    3












                    3








                    3







                    You can first sort the hash:



                    sorted = hash.sort_by { |key, value| value[1].to_f }
                    
# => [[352, ["socks", "3.99"]], [456, ["pants", "49.50"]], [124, ["shoes", "59.99"]]]


                    And then you can select the last pair:



                    sorted[-1]
                    
# => [124, ["shoes", "59.99"]]





                    share|improve this answer















                    You can first sort the hash:



                    sorted = hash.sort_by { |key, value| value[1].to_f }
                    
# => [[352, ["socks", "3.99"]], [456, ["pants", "49.50"]], [124, ["shoes", "59.99"]]]


                    And then you can select the last pair:



                    sorted[-1]
                    
# => [124, ["shoes", "59.99"]]






                    share|improve this answer














                    share|improve this answer



                    share|improve this answer








                    edited Nov 21 '18 at 17:52

























                    answered Nov 20 '18 at 21:55









                    jondavidjohnjondavidjohn

                    50.6k18100143




                    50.6k18100143








                    • 6





                      Or using max_by, hash.max_by { |k,v| v.last.to_f }

                      – Marcin Kołodziej
                      Nov 20 '18 at 22:04













                    • Thank you guys. You're a lifesaver.

                      – Tobyrrr00
                      Nov 20 '18 at 22:28






                    • 1





                      You are sorting the values alphabetically, not by their numerical value.

                      – Stefan
                      Nov 21 '18 at 7:42














                    • 6





                      Or using max_by, hash.max_by { |k,v| v.last.to_f }

                      – Marcin Kołodziej
                      Nov 20 '18 at 22:04













                    • Thank you guys. You're a lifesaver.

                      – Tobyrrr00
                      Nov 20 '18 at 22:28






                    • 1





                      You are sorting the values alphabetically, not by their numerical value.

                      – Stefan
                      Nov 21 '18 at 7:42








                    6




                    6





                    Or using max_by, hash.max_by { |k,v| v.last.to_f }

                    – Marcin Kołodziej
                    Nov 20 '18 at 22:04







                    Or using max_by, hash.max_by { |k,v| v.last.to_f }

                    – Marcin Kołodziej
                    Nov 20 '18 at 22:04















                    Thank you guys. You're a lifesaver.

                    – Tobyrrr00
                    Nov 20 '18 at 22:28





                    Thank you guys. You're a lifesaver.

                    – Tobyrrr00
                    Nov 20 '18 at 22:28




                    1




                    1





                    You are sorting the values alphabetically, not by their numerical value.

                    – Stefan
                    Nov 21 '18 at 7:42





                    You are sorting the values alphabetically, not by their numerical value.

                    – Stefan
                    Nov 21 '18 at 7:42











                    1














                    If you don’t mind the keys, another option could be:



                    h.values.map(&:reverse).max



                    #=> ["59.99", "shoes"]






                    share|improve this answer
























                    • Notice that this compares the prices as strings, not as floats, and it is not certain whether the OP wanted that.

                      – sawa
                      Nov 21 '18 at 3:12
















                    1














                    If you don’t mind the keys, another option could be:



                    h.values.map(&:reverse).max



                    #=> ["59.99", "shoes"]






                    share|improve this answer
























                    • Notice that this compares the prices as strings, not as floats, and it is not certain whether the OP wanted that.

                      – sawa
                      Nov 21 '18 at 3:12














                    1












                    1








                    1







                    If you don’t mind the keys, another option could be:



                    h.values.map(&:reverse).max



                    #=> ["59.99", "shoes"]






                    share|improve this answer













                    If you don’t mind the keys, another option could be:



                    h.values.map(&:reverse).max



                    #=> ["59.99", "shoes"]







                    share|improve this answer












                    share|improve this answer



                    share|improve this answer










                    answered Nov 20 '18 at 22:34









                    iGianiGian

                    3,6452622




                    3,6452622













                    • Notice that this compares the prices as strings, not as floats, and it is not certain whether the OP wanted that.

                      – sawa
                      Nov 21 '18 at 3:12



















                    • Notice that this compares the prices as strings, not as floats, and it is not certain whether the OP wanted that.

                      – sawa
                      Nov 21 '18 at 3:12

















                    Notice that this compares the prices as strings, not as floats, and it is not certain whether the OP wanted that.

                    – sawa
                    Nov 21 '18 at 3:12





                    Notice that this compares the prices as strings, not as floats, and it is not certain whether the OP wanted that.

                    – sawa
                    Nov 21 '18 at 3:12


















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