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  4. How to define static members in a static function in .cpp file?
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How to define static members in a static function in .cpp file?

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  • J jsulm
    4 Feb 2019, 08:12

    @thippu Not really what I asked...
    Did you add

    double AmpConfiguration::sampling_rate;
    

    to your cpp file?

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    thippu
    wrote on 4 Feb 2019, 08:24 last edited by
    #7

    @jsulm yes bro, I did add like this double AmpConfiguration::sampling_rate=line_list->at(0).toDouble();
    but new error came qualified-id decalration before "=" token

    J 1 Reply Last reply 4 Feb 2019, 08:25
    0
    • T thippu
      4 Feb 2019, 08:24

      @jsulm yes bro, I did add like this double AmpConfiguration::sampling_rate=line_list->at(0).toDouble();
      but new error came qualified-id decalration before "=" token

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      jsulm
      Lifetime Qt Champion
      wrote on 4 Feb 2019, 08:25 last edited by jsulm 2 Apr 2019, 08:27
      #8

      @thippu said in How to define static members in a static function in .cpp file?:

      double AmpConfiguration::sampling_rate=line_list->at(0).toDouble();

      Please read again what I wrote.
      Where do you call this now?
      It looks like you're now trying to declare a LOCAL variable with same name which is for sure not what you want to do.

      https://forum.qt.io/topic/113070/qt-code-of-conduct

      T 1 Reply Last reply 4 Feb 2019, 08:26
      0
      • J jsulm
        4 Feb 2019, 08:25

        @thippu said in How to define static members in a static function in .cpp file?:

        double AmpConfiguration::sampling_rate=line_list->at(0).toDouble();

        Please read again what I wrote.
        Where do you call this now?
        It looks like you're now trying to declare a LOCAL variable with same name which is for sure not what you want to do.

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        thippu
        wrote on 4 Feb 2019, 08:26 last edited by
        #9

        @jsulm said in How to define static members in a static function in .cpp file?:

        Where do you call this now?

        In the mainwindow.cpp

        J 1 Reply Last reply 4 Feb 2019, 08:27
        0
        • T thippu
          4 Feb 2019, 08:26

          @jsulm said in How to define static members in a static function in .cpp file?:

          Where do you call this now?

          In the mainwindow.cpp

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          jsulm
          Lifetime Qt Champion
          wrote on 4 Feb 2019, 08:27 last edited by
          #10

          @thippu said in How to define static members in a static function in .cpp file?:

          In the mainwindow.cpp

          WHERE EXACTLY?

          https://forum.qt.io/topic/113070/qt-code-of-conduct

          T 1 Reply Last reply 4 Feb 2019, 08:30
          0
          • J jsulm
            4 Feb 2019, 08:27

            @thippu said in How to define static members in a static function in .cpp file?:

            In the mainwindow.cpp

            WHERE EXACTLY?

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            thippu
            wrote on 4 Feb 2019, 08:30 last edited by thippu 2 Apr 2019, 08:31
            #11

            @jsulm
            In the constructor of mainwindow.cpp
            I'm calling AmpConfiguration::ReadIni(); First statement itself

            J 1 Reply Last reply 4 Feb 2019, 08:33
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            • T thippu
              4 Feb 2019, 08:30

              @jsulm
              In the constructor of mainwindow.cpp
              I'm calling AmpConfiguration::ReadIni(); First statement itself

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              jsulm
              Lifetime Qt Champion
              wrote on 4 Feb 2019, 08:33 last edited by
              #12

              @thippu Can you actually be more precise when answering questions?
              Do you mean you put that line in the constructor or inside ReadIni()?
              But as I said: you're declaring a local variable with same name.
              It must be like this:

              AmpConfiguration::sampling_rate=line_list->at(0).toDouble();
              

              AmpConfiguration:: can be removed as well...

              https://forum.qt.io/topic/113070/qt-code-of-conduct

              T 2 Replies Last reply 4 Feb 2019, 08:41
              1
              • J jsulm
                4 Feb 2019, 08:33

                @thippu Can you actually be more precise when answering questions?
                Do you mean you put that line in the constructor or inside ReadIni()?
                But as I said: you're declaring a local variable with same name.
                It must be like this:

                AmpConfiguration::sampling_rate=line_list->at(0).toDouble();
                

                AmpConfiguration:: can be removed as well...

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                thippu
                wrote on 4 Feb 2019, 08:41 last edited by
                #13

                @jsulm said in How to define static members in a static function in .cpp file?:

                local variable

                I would like it to be a global static variable.

                and I would like to use it(initialize) inside AmpConfiguration::ReadIni()

                @jsulm said in How to define static members in a static function in .cpp file?:

                AmpConfiguration::sampling_rate=line_list->at(0).toDouble();

                finally, Calling the AmpConfiguration::ReadIni()in constructor of mainwindow.cpp.

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                • J jsulm
                  4 Feb 2019, 08:33

                  @thippu Can you actually be more precise when answering questions?
                  Do you mean you put that line in the constructor or inside ReadIni()?
                  But as I said: you're declaring a local variable with same name.
                  It must be like this:

                  AmpConfiguration::sampling_rate=line_list->at(0).toDouble();
                  

                  AmpConfiguration:: can be removed as well...

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                  thippu
                  wrote on 4 Feb 2019, 08:44 last edited by
                  #14

                  @jsulm said in How to define static members in a static function in .cpp file?:

                  AmpConfiguration::sampling_rate=line_list->at(0).toDouble();

                  No, change in the error. still, I'm getting undefined reference

                  J 1 Reply Last reply 4 Feb 2019, 08:54
                  0
                  • T thippu
                    4 Feb 2019, 08:44

                    @jsulm said in How to define static members in a static function in .cpp file?:

                    AmpConfiguration::sampling_rate=line_list->at(0).toDouble();

                    No, change in the error. still, I'm getting undefined reference

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                    jsulm
                    Lifetime Qt Champion
                    wrote on 4 Feb 2019, 08:54 last edited by jsulm 2 Apr 2019, 08:59
                    #15

                    @thippu "I would like it to be a global static variable." - then why do you declare it as local variable?
                    Did you put

                    double AmpConfiguration::sampling_rate=10.2; // This has to be OUTSIDE of any method/constructor
                    void AmpConfiguration::ReadIni()
                    {
                        sampling_rate=line_list->at(0).toDouble();
                    }
                    

                    as I already wrote above?
                    Please read about static members in C++.

                    https://forum.qt.io/topic/113070/qt-code-of-conduct

                    T 1 Reply Last reply 4 Feb 2019, 09:32
                    3
                    • J jsulm
                      4 Feb 2019, 08:54

                      @thippu "I would like it to be a global static variable." - then why do you declare it as local variable?
                      Did you put

                      double AmpConfiguration::sampling_rate=10.2; // This has to be OUTSIDE of any method/constructor
                      void AmpConfiguration::ReadIni()
                      {
                          sampling_rate=line_list->at(0).toDouble();
                      }
                      

                      as I already wrote above?
                      Please read about static members in C++.

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                      thippu
                      wrote on 4 Feb 2019, 09:32 last edited by
                      #16

                      @jsulm said in How to define static members in a static function in .cpp file?:

                      // This has to be OUTSIDE of any method/constructor

                      Worked. bro
                      Thank you

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                      4 Feb 2019, 09:32

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