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When reading QJsonArray it gives always 0

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qt5qjsonarrayreading
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  • J.HilkJ Offline
    J.HilkJ Offline
    J.Hilk
    Moderators
    wrote on last edited by
    #4

    do not localize your json, stick with the norm and use a dot as a separator for your double/floats


    Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


    Q: What's that?
    A: It's blue light.
    Q: What does it do?
    A: It turns blue.

    D 1 Reply Last reply
    5
    • D deleted286

      @jsulm it is to long i wanted to cut them but i forgot some paranthesis.

      Here is

      {
         "Genel":[
            {
               "Dns Ivme Ktsy:":"41,123",
               "Dns Msf Ktsy:":"451,52",
               "Dnste Dumen:":"1,3",
               "Dnste Gaz:":"6,3",
               "Dnste Yks r Aci Lmt:":"5.1",
               "Dnste Yksls:":"78,56",
               "Gaz Alt Limit:":"454,555",
               "Gps Bekleme Aci":"9,3",
               "Ize Yklsm Msf:":"12,36",
               "Kesisme Aci:":"55.47",
               "Nkt Kabul:":"52,36",
               "Telemetri Sklk:":"1215,15",
               "Yksls r Aci Lmt:":"7,3"
            }
         ],
         "A":[
            {
               "Abc":"11,48855",
               "Max:":"6,3",
               "Min:":"5,3",
               "Kg":"7,4"
            }
         ],
         "PID":[
            {
               "Alcalis aci:":"2,3",
               "G D Kznc":"96,3",
               "G I Kznc:":"4,36",
               "G Kmt Lmt:":"74.6",
               "G P Kznc:":"4,25",
               "IAS D Kznc:":"21,541",
               "IAS I Kznc:":"69,3",
               "IAS P Kznc:":"5,36",
               "P D Kznc":"45",
               "P I Kznc:":"335",
               "P Kmt Kznc:":"254",
               "P P Kznc:":"22",
               "R D Kznc:":"6",
               "R I Kznc:":"5",
               "R Kmt Lmt:":"2",
               "R P Kznc:":"4",
               "Y D Kzncn:":"44,6",
               "Y I Kzncn:":"2,3",
               "Y Kmt Lmt:":"7,5",
               "Y P Kzncn:":"3,6",
               "Ykls D Kznc:":"7,32",
               "Ykls I Kznc:":"5,25",
               "Yksls Aci:":"7,3",
               "Yksls P Kznc:":"2,36",
               "Yon Aci:":"9,1",
               "Yon D Kznc:":"7,5",
               "Yon I Kznc:":"3,6",
               "Yon P Kznc:":"45.23"
            }
         ],
         "Servo":[
            {
               "Alt Nkt:":"7,32",
               "Motor Yon :":"23,63",
               "Sag Ana Knt Aci orta:":"5,3",
               "Sag Ana Knt Alt Nkt:":"3,2",
               "Sag Ana Knt Orta Nkt:":"7,5",
               "Sag Ana Knt Ust Nkt:":"9,6",
               "Sag Ana Knt Yon:":"1,2",
               "Sag Arka Knt Aci orta:":"47,12",
               "Sag Arka Knt Alt Nkt:":"23,5",
               "Sag Arka Knt Orta Nkt:":"78,21",
               "Sag Arka Knt Ust Nkt:":"12,25",
               "Sag Arka Knt Yon:":"2,5",
               "Sol Ana Knt Aci orta:":"7,5",
               "Sol Ana Knt Alt Nkt:":"7,5",
               "Sol Ana Knt Orta Nkt:":"1,2",
               "Sol Ana Knt Ust Nkt:":"9,2",
               "Sol Ana Knt Yon:":"4,5",
               "Sol Arka Knt Aci orta:":"",
               "Sol Arka Knt Alt Nkt:":"",
               "Sol Arka Knt Orta Nkt:":"",
               "Sol Arka Knt Ust Nkt:":"",
               "Sol Arka Knt Yon:":"",
               "Ust Nkt:":"77,23"
            }
         ],
         "Seyir":[
            {
               "Mncnk Klks Btrm Sure:":"23,21",
               "Mncnk Klks Btrm Yksklk:":"4,21",
               "Motor Kpt Lmt ":"12,36",
               "Perdo Hiz:":"231,56",
               "Perdo Sakinma Aci":"12,25",
               "Pitch Trim:":"2,3",
               "Prst Rota Zmn Asim:":"7,36",
               "Roll Trim:":"4,21",
               "Seyir Hizi IAS:":"23,15",
               "Seyir Zmn Asim:":"4,12",
               "Stab Zmn Asim:":"45566",
               "Yaw Trim:":"4,26"
            }
         ]
      }
      
      Christian EhrlicherC Offline
      Christian EhrlicherC Offline
      Christian Ehrlicher
      Lifetime Qt Champion
      wrote on last edited by
      #5

      @suslucoder said in When reading QJsonArray it gives always 0:

      "11,48855",

      This is a string, no double.

      Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
      Visit the Qt Academy at https://academy.qt.io/catalog

      D 1 Reply Last reply
      4
      • J.HilkJ J.Hilk

        do not localize your json, stick with the norm and use a dot as a separator for your double/floats

        D Offline
        D Offline
        deleted286
        wrote on last edited by
        #6

        @J-Hilk said in When reading QJsonArray it gives always 0:

        do not localize your json, stick with the norm and use a dot as a separator for your double/floats

        I use dot but it wont change anything. I cant read

        Christian EhrlicherC jsulmJ 2 Replies Last reply
        0
        • D deleted286

          @J-Hilk said in When reading QJsonArray it gives always 0:

          do not localize your json, stick with the norm and use a dot as a separator for your double/floats

          I use dot but it wont change anything. I cant read

          Christian EhrlicherC Offline
          Christian EhrlicherC Offline
          Christian Ehrlicher
          Lifetime Qt Champion
          wrote on last edited by
          #7

          @suslucoder said in When reading QJsonArray it gives always 0:

          I cant read

          Please read my post...

          Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
          Visit the Qt Academy at https://academy.qt.io/catalog

          1 Reply Last reply
          0
          • D deleted286

            @J-Hilk said in When reading QJsonArray it gives always 0:

            do not localize your json, stick with the norm and use a dot as a separator for your double/floats

            I use dot but it wont change anything. I cant read

            jsulmJ Offline
            jsulmJ Offline
            jsulm
            Lifetime Qt Champion
            wrote on last edited by
            #8
            This post is deleted!
            1 Reply Last reply
            0
            • Christian EhrlicherC Christian Ehrlicher

              @suslucoder said in When reading QJsonArray it gives always 0:

              "11,48855",

              This is a string, no double.

              D Offline
              D Offline
              deleted286
              wrote on last edited by
              #9

              @Christian-Ehrlicher but 5.0 is double? I've changed the value

              1 Reply Last reply
              0
              • Christian EhrlicherC Offline
                Christian EhrlicherC Offline
                Christian Ehrlicher
                Lifetime Qt Champion
                wrote on last edited by Christian Ehrlicher
                #10

                @suslucoder said in When reading QJsonArray it gives always 0:

                but 5.0 is double?

                It's not 5.0 but "5.0" and this is a string. See also QJsonValue::Type()

                Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
                Visit the Qt Academy at https://academy.qt.io/catalog

                1 Reply Last reply
                4
                • sierdzioS Offline
                  sierdzioS Offline
                  sierdzio
                  Moderators
                  wrote on last edited by
                  #11

                  @suslucoder JSON does not convert strings to numbers. So if a value is string and you try to read a double, it will always return 0.

                  A workaround for this is:

                  qDebug() << "Abc:" << grvArray[i].toObject()["Abc"].toVariant().toInt();
                  

                  Although it does come with it's problems.

                  (Z(:^

                  J.HilkJ D 2 Replies Last reply
                  2
                  • sierdzioS sierdzio

                    @suslucoder JSON does not convert strings to numbers. So if a value is string and you try to read a double, it will always return 0.

                    A workaround for this is:

                    qDebug() << "Abc:" << grvArray[i].toObject()["Abc"].toVariant().toInt();
                    

                    Although it does come with it's problems.

                    J.HilkJ Offline
                    J.HilkJ Offline
                    J.Hilk
                    Moderators
                    wrote on last edited by
                    #12

                    @sierdzio ok, when we start to give etchy solutions 😉

                    Local local(QLocale::German);
                    qDebug() << "Abc:" << l.toDouble(grvArray[i].toObject()["Abc"].toString());
                    

                    Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                    Q: What's that?
                    A: It's blue light.
                    Q: What does it do?
                    A: It turns blue.

                    1 Reply Last reply
                    1
                    • sierdzioS Offline
                      sierdzioS Offline
                      sierdzio
                      Moderators
                      wrote on last edited by
                      #13

                      It's etchiness depends on particular case. In some applications, JSON is used as an internal format, where rules can be different than official ones. And being able to specify a number by either string or number is useful.

                      Plus, let's not forget JSON does not support integers at all. So if you want to specify an integer and be sure it won't be fuzzy, using a string is OK.

                      (Z(:^

                      1 Reply Last reply
                      0
                      • JonBJ Offline
                        JonBJ Offline
                        JonB
                        wrote on last edited by
                        #14

                        I don't know where @suslucoder gets his JSON from. And I admit in my code I save/restore integers (C++ type) not floating point. But for integers at least I note that Qt JSON saves as a number, not as a string. So I imagine it would save a floating point similarly. Just saying.

                        D 1 Reply Last reply
                        0
                        • JonBJ JonB

                          I don't know where @suslucoder gets his JSON from. And I admit in my code I save/restore integers (C++ type) not floating point. But for integers at least I note that Qt JSON saves as a number, not as a string. So I imagine it would save a floating point similarly. Just saying.

                          D Offline
                          D Offline
                          deleted286
                          wrote on last edited by
                          #15

                          @JonB ı didnt get my json from anywhere. I create it by myself

                          JonBJ 1 Reply Last reply
                          0
                          • sierdzioS sierdzio

                            @suslucoder JSON does not convert strings to numbers. So if a value is string and you try to read a double, it will always return 0.

                            A workaround for this is:

                            qDebug() << "Abc:" << grvArray[i].toObject()["Abc"].toVariant().toInt();
                            

                            Although it does come with it's problems.

                            D Offline
                            D Offline
                            deleted286
                            wrote on last edited by
                            #16

                            @sierdzio I did it like this way. But it cant read some datas still. What should be the reason? It reads the first and last element of 1 array. And then, didnt read the second item of an array. Read the 4.element of array 2. I didnt understand

                            1 Reply Last reply
                            0
                            • Christian EhrlicherC Offline
                              Christian EhrlicherC Offline
                              Christian Ehrlicher
                              Lifetime Qt Champion
                              wrote on last edited by
                              #17

                              Since you created the json manually you're mixing . and ,. Use the proper json notation for doubles without quotes if you want that someone else will be able to read them and don't create such files manually.

                              Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
                              Visit the Qt Academy at https://academy.qt.io/catalog

                              D 1 Reply Last reply
                              4
                              • Christian EhrlicherC Christian Ehrlicher

                                Since you created the json manually you're mixing . and ,. Use the proper json notation for doubles without quotes if you want that someone else will be able to read them and don't create such files manually.

                                D Offline
                                D Offline
                                deleted286
                                wrote on last edited by
                                #18

                                @Christian-Ehrlicher I have LineEdit. I take datas from line edit on my qui, and save those datas in txt file which is formatted json. I want to take float or double nums on line edit.

                                I have " " because line edit accept strings.

                                Pl45m4P 1 Reply Last reply
                                0
                                • D deleted286

                                  @Christian-Ehrlicher I have LineEdit. I take datas from line edit on my qui, and save those datas in txt file which is formatted json. I want to take float or double nums on line edit.

                                  I have " " because line edit accept strings.

                                  Pl45m4P Online
                                  Pl45m4P Online
                                  Pl45m4
                                  wrote on last edited by Pl45m4
                                  #19

                                  @suslucoder said in When reading QJsonArray it gives always 0:

                                  I have " " because line edit accept strings.

                                  But you cant save strings in the same way as you save floats / doubles or ints (edit: No ints).

                                  @Christian-Ehrlicher said in When reading QJsonArray it gives always 0:

                                  It's not 5.0 but "5.0" and this is a string. See also QJsonValue::Type()

                                  That's what @Christian-Ehrlicher said here

                                  So you have to differentiate what is going to be stored in your Json.
                                  (If you build your Json yourself -> strings with "....." and floats with . as separator to avoid read errors)

                                  You can save everything as string, but then you have to convert it when reading the values again (-> also works best when using a dot as separator. Not every locale supports , as decimal separator. This is why you probably got 0)


                                  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
                                  2
                                  • JonBJ Offline
                                    JonBJ Offline
                                    JonB
                                    wrote on last edited by
                                    #20

                                    @suslucoder
                                    ...Which is why I suggested you might choose to save/put in file 41.123 instead of string with quotes like your "41,123", then you will be storing a number and won't have to convert from a string....

                                    1 Reply Last reply
                                    2
                                    • Christian EhrlicherC Offline
                                      Christian EhrlicherC Offline
                                      Christian Ehrlicher
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #21

                                      Or use a proper QDoubleSpinbox

                                      Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
                                      Visit the Qt Academy at https://academy.qt.io/catalog

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                                      0
                                      • Pl45m4P Online
                                        Pl45m4P Online
                                        Pl45m4
                                        wrote on last edited by
                                        #22

                                        Or a QLineEdit with an input mask, so you can be sure that is input of this widget gonna be a number. Then you can write it as double to your Json.

                                        https://doc.qt.io/qt-5/qlineedit.html#inputMask-prop


                                        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
                                        0
                                        • D deleted286

                                          @JonB ı didnt get my json from anywhere. I create it by myself

                                          JonBJ Offline
                                          JonBJ Offline
                                          JonB
                                          wrote on last edited by
                                          #23

                                          @suslucoder said in When reading QJsonArray it gives always 0:

                                          ı didnt get my json from anywhere. I create it by myself

                                          So this is not a widget issue, at least at this stage. It's a question of OP deciding on a type to be used in the JSON.

                                          1 Reply Last reply
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