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Facepalm of the day.

Scheduled Pinned Locked Moved The Weird and The Wonderful
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  • J Jorgen Andersson

    If I don't expect the conversion to fail I want an exception. When failure is expected I use TryParse. There is a reason both exists.

    Wrong is evil and must be defeated. - Jeff Ello[^]

    P Offline
    P Offline
    PIEBALDconsult
    wrote on last edited by
    #11

    Yes, in this case Parse is more appropriate. (I just updated my earlier response with an example.)

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    • J Jorgen Andersson

      And we have a winner. Amazing that the decimal point is making the conversion more than 3000 times slower. But since it didn't throw an exception but rather make a correct conversion I actually doubt that TryParse would have made a difference.

      Wrong is evil and must be defeated. - Jeff Ello[^]

      Richard DeemingR Offline
      Richard DeemingR Offline
      Richard Deeming
      wrote on last edited by
      #12

      Jörgen Andersson wrote:

      But since it didn't throw an exception but rather make a correct conversion

      What version of .NET? I've just tried Convert.ToInt32("42.") in LINQPad for 3.5 and 4.5, and both versions throw a FormatException.


      "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

      "These people looked deep within my soul and assigned me a number based on the order in which I joined" - Homer

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      • L Lost User

        Your length is off by one. The decimal point is included. I prefer int.TryParse over Convert.

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        Ian Shlasko
        wrote on last edited by
        #13

        That slows it down? I spotted that right away, about 15 mins after he posted, but figured it'd be irrelevant, so didn't post. So a trailing decimal has that much of an effect... Good to know.

        Proud to have finally moved to the A-Ark. Which one are you in?
        Author of the Guardians Saga (Sci-Fi/Fantasy novels)

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        • J Jorgen Andersson

          And we have a winner. Amazing that the decimal point is making the conversion more than 3000 times slower. But since it didn't throw an exception but rather make a correct conversion I actually doubt that TryParse would have made a difference.

          Wrong is evil and must be defeated. - Jeff Ello[^]

          I Offline
          I Offline
          Ian Shlasko
          wrote on last edited by
          #14

          3000 times slower? I noticed the extra character about 15 mins after you started this thread, but didn't think it relevant. I'll have to keep an eye out for that... Almost as bad as the exponent operator in VB.NET... (Try benchmarking 2^2 vs Math.Pow(2,2))

          Proud to have finally moved to the A-Ark. Which one are you in?
          Author of the Guardians Saga (Sci-Fi/Fantasy novels)

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          • Richard DeemingR Richard Deeming

            Jörgen Andersson wrote:

            But since it didn't throw an exception but rather make a correct conversion

            What version of .NET? I've just tried Convert.ToInt32("42.") in LINQPad for 3.5 and 4.5, and both versions throw a FormatException.


            "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

            J Offline
            J Offline
            Jorgen Andersson
            wrote on last edited by
            #15

            4.5

            Wrong is evil and must be defeated. - Jeff Ello[^]

            Richard DeemingR 1 Reply Last reply
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            • J Jorgen Andersson

              4.5

              Wrong is evil and must be defeated. - Jeff Ello[^]

              Richard DeemingR Offline
              Richard DeemingR Offline
              Richard Deeming
              wrote on last edited by
              #16

              Weird. If I try Convert.ToInt32("42.") in .NET 4.5, I get: FormatException: Input string was not in a correct format. Are you sure you're not doing something else in your code that's hiding the error?


              "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

              "These people looked deep within my soul and assigned me a number based on the order in which I joined" - Homer

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              • Richard DeemingR Richard Deeming

                Weird. If I try Convert.ToInt32("42.") in .NET 4.5, I get: FormatException: Input string was not in a correct format. Are you sure you're not doing something else in your code that's hiding the error?


                "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                J Offline
                J Offline
                Jorgen Andersson
                wrote on last edited by
                #17

                Odd, I'have to check on monday when I'm back at work.

                Wrong is evil and must be defeated. - Jeff Ello[^]

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                • Richard DeemingR Richard Deeming

                  Weird. If I try Convert.ToInt32("42.") in .NET 4.5, I get: FormatException: Input string was not in a correct format. Are you sure you're not doing something else in your code that's hiding the error?


                  "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                  R Offline
                  R Offline
                  Robert Rohde
                  wrote on last edited by
                  #18

                  Jörgen Andersson (is this you "Neo"?!?) sounds scandinavian and they probably have a different decimal separator... Robert

                  Richard DeemingR 1 Reply Last reply
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                  • R Robert Rohde

                    Jörgen Andersson (is this you "Neo"?!?) sounds scandinavian and they probably have a different decimal separator... Robert

                    Richard DeemingR Offline
                    Richard DeemingR Offline
                    Richard Deeming
                    wrote on last edited by
                    #19

                    Good point. However, Convert.ToInt32("42,") still produces a FormatException. Trying "42." with the "sv-SE" culture, which uses "," as the decimal separator and "." as the group separator, also produces a FormatException.


                    "These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

                    "These people looked deep within my soul and assigned me a number based on the order in which I joined" - Homer

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                    • J Jorgen Andersson

                      So I was building an application that presents a list of files matched with info in a database. Everything was working fine and dandy but horrendously slow. I quickly found the culprit to be in this function:

                      Func GetIDPart_Of_FileName = FileName => Convert.ToInt32(FileName.Substring(FileName.IndexOf('_') + 1, FileName.IndexOf('.') - FileName.IndexOf('_')));

                      The files are built in the form of ID_AnotherID.Extension and what I wanted was AnotherID Can anyone see what I did wrong? :) Do note that it was giving correct results. fixed typo

                      Wrong is evil and must be defeated. - Jeff Ello[^]

                      O Offline
                      O Offline
                      Omar Gameel Salem
                      wrote on last edited by
                      #20

                      hmm FileName.IndexOf('_') is calculated twice too

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                      • J Jorgen Andersson

                        So I was building an application that presents a list of files matched with info in a database. Everything was working fine and dandy but horrendously slow. I quickly found the culprit to be in this function:

                        Func GetIDPart_Of_FileName = FileName => Convert.ToInt32(FileName.Substring(FileName.IndexOf('_') + 1, FileName.IndexOf('.') - FileName.IndexOf('_')));

                        The files are built in the form of ID_AnotherID.Extension and what I wanted was AnotherID Can anyone see what I did wrong? :) Do note that it was giving correct results. fixed typo

                        Wrong is evil and must be defeated. - Jeff Ello[^]

                        M Offline
                        M Offline
                        Marc Clifton
                        wrote on last edited by
                        #21

                        Well, a little late to the party, but this is why I have a whole bunch of string extensions, like this "Between" and "ToInt32": FileName.Between('_', '.').ToInt32() And then you would never have included the '.' by accident. ;) Marc

                        Imperative to Functional Programming Succinctly Higher Order Programming

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                        • M Marc Clifton

                          Well, a little late to the party, but this is why I have a whole bunch of string extensions, like this "Between" and "ToInt32": FileName.Between('_', '.').ToInt32() And then you would never have included the '.' by accident. ;) Marc

                          Imperative to Functional Programming Succinctly Higher Order Programming

                          J Offline
                          J Offline
                          Jorgen Andersson
                          wrote on last edited by
                          #22

                          Just put that on my todo list. :thumbsup:

                          Wrong is evil and must be defeated. - Jeff Ello[^]

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                          • J Jorgen Andersson

                            Just put that on my todo list. :thumbsup:

                            Wrong is evil and must be defeated. - Jeff Ello[^]

                            M Offline
                            M Offline
                            Marc Clifton
                            wrote on last edited by
                            #23

                            Send me a direct email and I'll send you the .cs file of my extensions. There's this[^] too. Marc

                            Imperative to Functional Programming Succinctly Higher Order Programming

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                            • M Marc Clifton

                              Well, a little late to the party, but this is why I have a whole bunch of string extensions, like this "Between" and "ToInt32": FileName.Between('_', '.').ToInt32() And then you would never have included the '.' by accident. ;) Marc

                              Imperative to Functional Programming Succinctly Higher Order Programming

                              G Offline
                              G Offline
                              Garth J Lancaster
                              wrote on last edited by
                              #24

                              very cool (aka :cool: ) 'g'

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