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  4. problems on using the if and else statement and updating the data.

problems on using the if and else statement and updating the data.

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c++ qtupdateif and else
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  • JonBJ JonB

    @sierdzio said in problems on using the if and else statement and updating the data.:

    All modernt compilers also understand and as a synonym to && so you can do:

    I am speechless! Apart from the fact that I have never heard of this (old time C/C++ programmer, now returned to new C++). And apart from the fact that introducing and as a language keyword would potentially break one million old C/C++ programs which could have used and as a variable?

    You are obviously more expert than I, but do you want to recommend this to a newbie? I have never noticed and used in a C++ program, if OP is to produce standard code, and recognize others' code, would you not recommend sticking with &&?

    J.HilkJ Online
    J.HilkJ Online
    J.Hilk
    Moderators
    wrote on last edited by
    #9

    @JonB apparently part of the standard since c++98
    https://en.cppreference.com/w/cpp/keyword/and


    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.

    JonBJ 1 Reply Last reply
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    • J.HilkJ J.Hilk

      @JonB apparently part of the standard since c++98
      https://en.cppreference.com/w/cpp/keyword/and

      JonBJ Offline
      JonBJ Offline
      JonB
      wrote on last edited by JonB
      #10

      @J-Hilk , @sierdzio
      Absolutely shocking! I see from https://en.cppreference.com/w/cpp/language/operator_alternative that there are actually 11 new reserved words for operators. Including not, and even the string compl, which I might have used as variables and would break upgrading to C++ '98.

      Thinking aloud, I believe all C operators were symbols and not words, part of the charm (for right or for wrong) of the language.

      With all due respect to @sierdzio's comment, which I accept & respect, I have still never seen a piece of C++ code using any of these.... [And hence would caution a beginner against adopting these.]

      [C++ looks like it's trying to be a Python-wannabe ;-) ]

      jsulmJ 1 Reply Last reply
      1
      • JonBJ JonB

        @J-Hilk , @sierdzio
        Absolutely shocking! I see from https://en.cppreference.com/w/cpp/language/operator_alternative that there are actually 11 new reserved words for operators. Including not, and even the string compl, which I might have used as variables and would break upgrading to C++ '98.

        Thinking aloud, I believe all C operators were symbols and not words, part of the charm (for right or for wrong) of the language.

        With all due respect to @sierdzio's comment, which I accept & respect, I have still never seen a piece of C++ code using any of these.... [And hence would caution a beginner against adopting these.]

        [C++ looks like it's trying to be a Python-wannabe ;-) ]

        jsulmJ Online
        jsulmJ Online
        jsulm
        Lifetime Qt Champion
        wrote on last edited by
        #11

        @JonB said in problems on using the if and else statement and updating the data.:

        I have still never seen a piece of C++ code using any of these

        Me neither :-)

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

        1 Reply Last reply
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        • sierdzioS Offline
          sierdzioS Offline
          sierdzio
          Moderators
          wrote on last edited by
          #12

          I have seen it but very, very rarely.

          And hence would caution a beginner against adopting these

          I'm split on this :D One one hand, && is clearly, vastly, totally the established and well-known convention practically everywhere. So using it is definitely a good idea.

          But on the other hand, and is more readable and convenient. So it is also a good idea.

          (Z(:^

          JonBJ 1 Reply Last reply
          1
          • sierdzioS sierdzio

            I have seen it but very, very rarely.

            And hence would caution a beginner against adopting these

            I'm split on this :D One one hand, && is clearly, vastly, totally the established and well-known convention practically everywhere. So using it is definitely a good idea.

            But on the other hand, and is more readable and convenient. So it is also a good idea.

            JonBJ Offline
            JonBJ Offline
            JonB
            wrote on last edited by JonB
            #13

            @sierdzio said in problems on using the if and else statement and updating the data.:

            But on the other hand, and is more readable and convenient.

            In Pascal or Python, yes. When scanning C/C++ I expect to see all operators as symbols (and not some but not others) Next C++ will be offering begin/end for {/}! [Some people used to do all this words-for-symbols via C #defines.] I give up on the modern world, it's all going to pot... ;-)

            J.HilkJ 1 Reply Last reply
            1
            • JonBJ JonB

              @sierdzio said in problems on using the if and else statement and updating the data.:

              But on the other hand, and is more readable and convenient.

              In Pascal or Python, yes. When scanning C/C++ I expect to see all operators as symbols (and not some but not others) Next C++ will be offering begin/end for {/}! [Some people used to do all this words-for-symbols via C #defines.] I give up on the modern world, it's all going to pot... ;-)

              J.HilkJ Online
              J.HilkJ Online
              J.Hilk
              Moderators
              wrote on last edited by
              #14

              @JonB said in problems on using the if and else statement and updating the data.:

              Next C++ will be offering begin/end for {/}!

              you can use

              {	??<
              }	??>
              [	??(
              ]	??)
              #	??=
              \	??/
              ^	??'
              |	??!
              ~	??-
              

              but that was removed in c++17, :)


              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.

              JonBJ 1 Reply Last reply
              1
              • J.HilkJ J.Hilk

                @JonB said in problems on using the if and else statement and updating the data.:

                Next C++ will be offering begin/end for {/}!

                you can use

                {	??<
                }	??>
                [	??(
                ]	??)
                #	??=
                \	??/
                ^	??'
                |	??!
                ~	??-
                

                but that was removed in c++17, :)

                JonBJ Offline
                JonBJ Offline
                JonB
                wrote on last edited by JonB
                #15

                @J-Hilk

                but that was removed in c++17, :)

                Even better --- you start using new language constructs and then they remove them so that your code gets broken!

                FWIW, I note from https://en.cppreference.com/w/cpp/language/operator_alternative

                There are alternative spellings for several operators and other tokens that use non-ISO646 characters.

                So the motivation never was "clarity", it's to do with people having funny keyboards....

                1 Reply Last reply
                1
                • SGaistS Offline
                  SGaistS Offline
                  SGaist
                  Lifetime Qt Champion
                  wrote on last edited by
                  #16

                  @JonB said in problems on using the if and else statement and updating the data.:

                  funny keyboards

                  The hardware is innocent ;-P

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

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                  • Kent-DorfmanK Offline
                    Kent-DorfmanK Offline
                    Kent-Dorfman
                    wrote on last edited by
                    #17

                    whats next, espousing the virtues of trigraphs?

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                    0
                    • 1 Offline
                      1 Offline
                      1Manui1
                      wrote on last edited by
                      #18

                      How did you do it now?

                      1 Reply Last reply
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