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  4. How Can i get array in another class

How Can i get array in another class

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  • D dziko147

    @jsulm

    // classeA.h
    std::array<QString,25> Inputs;
    
    // ClassA.cpp "UploadCSV"
    void UploadCSV::on_parambtn_2_clicked()
    {
    
        int compteur=0;
        QString cell0;
        QString cell3 ;
        for(int i=0;i<ui->tablewidget->rowCount();i++){
    
            QTableWidgetItem *cell7 = ui->tablewidget->item(i,7);
    
            QVariant myData7 = cell7->data(Qt::DisplayRole);
            if (myData7=="Core_meas"){
                cell0  = ui->tablewidget->item(i,0)->text();
                cell3 = ui->tablewidget->item(i,3)->text();
                Inputs[compteur]=cell3;
                qDebug() << "Inputs baby"<<Inputs[compteur] ;
                compteur++;
            }
    
        }
    
    
    }
    

    //in classB.

    UploadCSV *up;

    //in classB.cpp

    up=new UploadCSV();
    for(size_t i=0;i<up.Inputs->size();i++){
    qqDebug() << "this is data",up.Inputs[i]
    
    
    CP71C Offline
    CP71C Offline
    CP71
    wrote on last edited by
    #31

    @dziko147 said in How Can i get array in another class:

    up=new UploadCSV();
    for(size_t i=0;i<up.Inputs->size();i++){
    qqDebug() << "this is data",up.Inputs[i]

    Sorry, who calls the on_parambtn_2_clicked() function?

    1 Reply Last reply
    1
    • D dziko147

      @jsulm sorry I edited the code .

      I gave the expamle of classA and ClassB to be clearer .

      ClassA (UploadCSV ) is a Qwidget : Qdialog

      ClassB (Backend) is QObject .

      jsulmJ Offline
      jsulmJ Offline
      jsulm
      Lifetime Qt Champion
      wrote on last edited by
      #32

      @dziko147 Is this your real code:

      up=new UploadCSV();
      for(size_t i=0;i<up.Inputs->size();i++){
      qqDebug() << "this is data",up.Inputs[i]
      

      ?
      Because Items is filled when UploadCSV::on_parambtn_2_clicked() is called (at least according to code you posted). But you're printing Inputs just after creating UploadCSV instance (up)! So why should there be anything in Inputs?

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

      D 1 Reply Last reply
      3
      • D Offline
        D Offline
        dziko147
        wrote on last edited by
        #33

        @CP71 it's called in UploadCSV class (classA) .

        and inside this function I set data in Inputs[] .

        jsulmJ 1 Reply Last reply
        0
        • D dziko147

          @CP71 it's called in UploadCSV class (classA) .

          and inside this function I set data in Inputs[] .

          jsulmJ Offline
          jsulmJ Offline
          jsulm
          Lifetime Qt Champion
          wrote on last edited by jsulm
          #34

          @dziko147 said in How Can i get array in another class:

          it's called in UploadCSV class (classA) .

          Where exactly?! And what is classA?! This all is really confusing!
          up != classA

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

          D 1 Reply Last reply
          1
          • jsulmJ jsulm

            @dziko147 Is this your real code:

            up=new UploadCSV();
            for(size_t i=0;i<up.Inputs->size();i++){
            qqDebug() << "this is data",up.Inputs[i]
            

            ?
            Because Items is filled when UploadCSV::on_parambtn_2_clicked() is called (at least according to code you posted). But you're printing Inputs just after creating UploadCSV instance (up)! So why should there be anything in Inputs?

            D Offline
            D Offline
            dziko147
            wrote on last edited by
            #35

            @jsulm yes i understand you . So can you suggest a way to do this correctly ?

            jsulmJ SGaistS 2 Replies Last reply
            0
            • D dziko147

              @jsulm yes i understand you . So can you suggest a way to do this correctly ?

              jsulmJ Offline
              jsulmJ Offline
              jsulm
              Lifetime Qt Champion
              wrote on last edited by
              #36

              @dziko147 Yes, I can: use one instance of the class instead of two...

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

              1 Reply Last reply
              2
              • D dziko147

                @jsulm yes i understand you . So can you suggest a way to do this correctly ?

                SGaistS Offline
                SGaistS Offline
                SGaist
                Lifetime Qt Champion
                wrote on last edited by
                #37

                @dziko147 said in How Can i get array in another class:

                @jsulm yes i understand you . So can you suggest a way to do this correctly ?

                Something like it was explained in your other thread ?

                Interested in AI ? www.idiap.ch
                Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                1 Reply Last reply
                1
                • jsulmJ jsulm

                  @dziko147 said in How Can i get array in another class:

                  it's called in UploadCSV class (classA) .

                  Where exactly?! And what is classA?! This all is really confusing!
                  up != classA

                  D Offline
                  D Offline
                  dziko147
                  wrote on last edited by
                  #38

                  @jsulm forget classA and classB example .

                  So curretly we have UploadCSV class and BackendClass .
                  I would like to get array defined from UploadCSV in Backend class .

                  jsulmJ Pl45m4P 2 Replies Last reply
                  0
                  • D dziko147

                    @jsulm forget classA and classB example .

                    So curretly we have UploadCSV class and BackendClass .
                    I would like to get array defined from UploadCSV in Backend class .

                    jsulmJ Offline
                    jsulmJ Offline
                    jsulm
                    Lifetime Qt Champion
                    wrote on last edited by
                    #39

                    @dziko147 said in How Can i get array in another class:

                    I would like to get array defined from UploadCSV in Backend class

                    Then do so.
                    To get it you need the UploadCSV instance. How you get it in Backend I don't know as I don't have your code. There are different ways to do this. You can pass pointer to UploadCSV instance to Backend constructor for example.
                    But to be able to give a good advice we would need to know how you manage your UploadCSV and Backend instances.

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

                    1 Reply Last reply
                    2
                    • D Offline
                      D Offline
                      dziko147
                      wrote on last edited by
                      #40

                      @jsulm
                      currently I pass a pointer like this .
                      in backend.h

                      UploadCSV *up;
                      

                      in backend.cpp

                      up = new UploadCSV();
                      
                      CP71C jsulmJ 3 Replies Last reply
                      0
                      • D dziko147

                        @jsulm
                        currently I pass a pointer like this .
                        in backend.h

                        UploadCSV *up;
                        

                        in backend.cpp

                        up = new UploadCSV();
                        
                        CP71C Offline
                        CP71C Offline
                        CP71
                        wrote on last edited by CP71
                        #41

                        @dziko147
                        Here you are not passing a pointer but you are creating a new instance of class

                        1 Reply Last reply
                        1
                        • D dziko147

                          @jsulm
                          currently I pass a pointer like this .
                          in backend.h

                          UploadCSV *up;
                          

                          in backend.cpp

                          up = new UploadCSV();
                          
                          CP71C Offline
                          CP71C Offline
                          CP71
                          wrote on last edited by CP71
                          #42

                          @dziko147
                          Sorry, but my English is no good.
                          So maybe I can help you with an example.

                          63a538e9-5f5f-47a8-98f4-1fe03c5462a4-image.png

                          To link my example.
                          I think you are filling your array in obj1, but when you try to read it you use obj2.
                          You that know your project, have a sense what I write?

                          In short, these are possible ways to have your result:

                          • two or more instance of you class
                          • your object never fills the array
                          • your object fills the array but with an empty value
                          • in somewhere of your class clear your array before you use it

                          But in your case seems you have two instances of class

                          1 Reply Last reply
                          2
                          • D dziko147

                            @jsulm forget classA and classB example .

                            So curretly we have UploadCSV class and BackendClass .
                            I would like to get array defined from UploadCSV in Backend class .

                            Pl45m4P Offline
                            Pl45m4P Offline
                            Pl45m4
                            wrote on last edited by Pl45m4
                            #43

                            @dziko147

                            Now that I understand a bit more, I think the only issue here is that you dont click that button that will fill your array before you try to access the elements.

                            You fill your array here:

                            void UploadCSV::on_parambtn_2_clicked()
                            {
                            ....
                            if (myData7=="Core_meas"){
                                        cell0  = ui->tablewidget->item(i,0)->text();
                                        cell3 = ui->tablewidget->item(i,3)->text();
                                        Inputs[compteur]=cell3;  //  <---- HERE
                                        qDebug() << "Inputs baby"<<Inputs[compteur] ;
                                        compteur++;
                                    }
                            ....
                            
                            }
                            

                            That means the array is still empty right after creating the class instance.

                            up=new UploadCSV(); // <--- New, empty public array
                            for(size_t i=0;i<up.Inputs->size();i++){
                            qDebug() << "this is data",up.Inputs[i] // data access, but not clicked that button before
                            

                            Also, you need to have access to the "same" instance where your array is filled with data. (See @CP71 and @jsulm answers). This could be done by passing a pointer to that object with contains your data.


                            If debugging is the process of removing software bugs, then programming must be the process of putting them in.

                            ~E. W. Dijkstra

                            1 Reply Last reply
                            1
                            • D dziko147

                              @jsulm
                              currently I pass a pointer like this .
                              in backend.h

                              UploadCSV *up;
                              

                              in backend.cpp

                              up = new UploadCSV();
                              
                              jsulmJ Offline
                              jsulmJ Offline
                              jsulm
                              Lifetime Qt Champion
                              wrote on last edited by
                              #44

                              @dziko147 said in How Can i get array in another class:

                              currently I pass a pointer like this

                              No, you do not pass any pointers here.
                              What I mean is:

                              up = new UploadCSV();
                              Backend backend(up); // Here you pass pointer to up to Backend instance
                              

                              Of course you need to change the Backend constructor and store the pointer in Backend as member variable to be able to use it later.

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

                              1 Reply Last reply
                              4
                              • D Offline
                                D Offline
                                dziko147
                                wrote on last edited by
                                #45

                                thank you all for your help :) .

                                CP71C 1 Reply Last reply
                                0
                                • D dziko147

                                  thank you all for your help :) .

                                  CP71C Offline
                                  CP71C Offline
                                  CP71
                                  wrote on last edited by
                                  #46

                                  @dziko147
                                  You are welcome! :)

                                  1 Reply Last reply
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