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bool and BOOL

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  • T toxcct

    if you're coding in C, bool just don't exist (I prefer mention it, even it's obvious). in C++, bool is a native type. it weights 1 byte and takes the values 0_b_0000000**1** (true) or 0_b_0000000**0** (false). you can assign an integer to a bool. if it is different from 0, it equals the value "true", and will be automatically converted into 0_b_0000000**1** anyway. BOOL is different. it is an enum type inherited from the old C days. it's definition is like this :

    enum BOOL {
    FALSE = 0,
    TRUE
    };

    An enum is actually an int, which mean it weights 4 bytes (on a 32 bits system). apparently, Microsoft implements it in a different manner, so you have to be much more careful with it. for instance :

    //if defined like this :
    typedef int BOOL;

    //this can be a mistake :
    BOOL b = 4;
    if (b == true) {
    //never enters here
    // because 4 != 1
    }

    [VisualCalc][Binary Guide][CommDialogs] | [Forums Guidelines]

    modified on Tuesday, May 20, 2008 9:50 AM

    N Offline
    N Offline
    Nemanja Trifunovic
    wrote on last edited by
    #21

    toxcct wrote:

    if you're coding in C, bool just don't exist

    It did not exist in C89, but exists in C99[^]

    Programming Blog utf8-cpp

    1 Reply Last reply
    0
    • C Cedric Moonen

      toxcct wrote:

      doesn't a Byte having 8 bits

      Yes, so it is coded 0x00 to 0xFF (hexa representation) or 0b00000000 to 0b11111111 (binary representation).

      Cédric Moonen Software developer
      Charting control [v1.4]

      T Offline
      T Offline
      toxcct
      wrote on last edited by
      #22

      yes yes, fixed already ;)

      [VisualCalc][Binary Guide][CommDialogs] | [Forums Guidelines]

      1 Reply Last reply
      0
      • T toxcct

        Rajesh R Subramanian wrote:

        May be toxcct is on drugs today for a change

        come on, have you ever worked under linux ? Microsoft IS NOT the standard, even if 85% of the PCs worldwide are windows based... :doh:

        [VisualCalc][Binary Guide][CommDialogs] | [Forums Guidelines]

        C Offline
        C Offline
        Cedric Moonen
        wrote on last edited by
        #23

        toxcct wrote:

        have you ever worked under linux

        What kind of drug is that ? ;P

        Cédric Moonen Software developer
        Charting control [v1.4]

        T R 2 Replies Last reply
        0
        • C Cedric Moonen

          toxcct wrote:

          have you ever worked under linux

          What kind of drug is that ? ;P

          Cédric Moonen Software developer
          Charting control [v1.4]

          T Offline
          T Offline
          toxcct
          wrote on last edited by
          #24

          Cedric Moonen wrote:

          What kind of drug is that ?

          i'd better give up there ! lol

          [VisualCalc][Binary Guide][CommDialogs] | [Forums Guidelines]

          1 Reply Last reply
          0
          • J Jhony george

            hai all, about 'bool' i got idea... from all ur replies... but what about BOOL..? i am not clear...

            Born to win...!

            modified on Tuesday, May 20, 2008 11:57 PM

            CPalliniC Online
            CPalliniC Online
            CPallini
            wrote on last edited by
            #25

            BOOL is fully featured integer, for instance, you can do.

            // WEIRD BOOL (legal) programming
            BOOL b;
            b = 1000;
            b++;

            You can't do the same with a bool variable. [added] Well, I made a sanity check, and actually VC++ compiler gives just a warning on the following code

            bool b;
            b = 1000; // Warning here (loss of info), at runtime b becomes true.
            b++; // at runtime b remains true.

            [/added] As stated by someone (Rajesh ? toxcct?) this is a reminiscence of the C language gold ol days (C has not the bool keyword). Using an int to represent Yes/No pair is simply a matter of convention (and convenience). :)

            If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
            This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

            In testa che avete, signor di Ceprano?

            T 1 Reply Last reply
            0
            • C Cedric Moonen

              toxcct wrote:

              have you ever worked under linux

              What kind of drug is that ? ;P

              Cédric Moonen Software developer
              Charting control [v1.4]

              R Offline
              R Offline
              Rajesh R Subramanian
              wrote on last edited by
              #26

              I dunno. Azk CPallini. He'z da one who abuzez drug to answer queris realllly fazzt. He haz gud drugz and gud linkz. azk him plz. :laugh:

              Nobody can give you wiser advice than yourself. - Cicero .·´¯`·->Rajesh<-·´¯`·. Codeproject.com: Visual C++ MVP

              1 Reply Last reply
              0
              • R Rajesh R Subramanian

                May be toxcct is on drugs today for a change. :laugh:

                Nobody can give you wiser advice than yourself. - Cicero .·´¯`·->Rajesh<-·´¯`·. Codeproject.com: Visual C++ MVP

                CPalliniC Online
                CPalliniC Online
                CPallini
                wrote on last edited by
                #27

                I supposed too. :laugh:

                If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
                This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

                In testa che avete, signor di Ceprano?

                1 Reply Last reply
                0
                • CPalliniC CPallini

                  BOOL is fully featured integer, for instance, you can do.

                  // WEIRD BOOL (legal) programming
                  BOOL b;
                  b = 1000;
                  b++;

                  You can't do the same with a bool variable. [added] Well, I made a sanity check, and actually VC++ compiler gives just a warning on the following code

                  bool b;
                  b = 1000; // Warning here (loss of info), at runtime b becomes true.
                  b++; // at runtime b remains true.

                  [/added] As stated by someone (Rajesh ? toxcct?) this is a reminiscence of the C language gold ol days (C has not the bool keyword). Using an int to represent Yes/No pair is simply a matter of convention (and convenience). :)

                  If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
                  This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

                  T Offline
                  T Offline
                  toxcct
                  wrote on last edited by
                  #28

                  but one has to be careful with BOOL, as I stated at the end of my most here[^]

                  CPallini wrote:

                  C has not the bool keyword

                  looks like it has[^]

                  [VisualCalc][Binary Guide][CommDialogs] | [Forums Guidelines]

                  CPalliniC 1 Reply Last reply
                  0
                  • T toxcct

                    but one has to be careful with BOOL, as I stated at the end of my most here[^]

                    CPallini wrote:

                    C has not the bool keyword

                    looks like it has[^]

                    [VisualCalc][Binary Guide][CommDialogs] | [Forums Guidelines]

                    CPalliniC Online
                    CPalliniC Online
                    CPallini
                    wrote on last edited by
                    #29

                    toxcct wrote:

                    but one has to be careful with BOOL, as I stated at the end of my most here[^]

                    Indeed. C language implicit mapping of non-zero values to true and zero value to false is more coherent.

                    toxcct wrote:

                    looks like it has[^]

                    I saw it, but: shhhhhh, noone, except Nemanja, knows. :-D

                    If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
                    This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

                    In testa che avete, signor di Ceprano?

                    R 1 Reply Last reply
                    0
                    • CPalliniC CPallini

                      toxcct wrote:

                      but one has to be careful with BOOL, as I stated at the end of my most here[^]

                      Indeed. C language implicit mapping of non-zero values to true and zero value to false is more coherent.

                      toxcct wrote:

                      looks like it has[^]

                      I saw it, but: shhhhhh, noone, except Nemanja, knows. :-D

                      If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
                      This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

                      R Offline
                      R Offline
                      Rajesh R Subramanian
                      wrote on last edited by
                      #30

                      CPallini wrote:

                      I saw it, but: shhhhhh, noone, except Nemanja, knows.

                      Oh come on. You are a "C" lover. I would have expected you to know. :-D

                      Nobody can give you wiser advice than yourself. - Cicero .·´¯`·->Rajesh<-·´¯`·. Codeproject.com: Visual C++ MVP

                      CPalliniC 1 Reply Last reply
                      0
                      • R Rajesh R Subramanian

                        CPallini wrote:

                        I saw it, but: shhhhhh, noone, except Nemanja, knows.

                        Oh come on. You are a "C" lover. I would have expected you to know. :-D

                        Nobody can give you wiser advice than yourself. - Cicero .·´¯`·->Rajesh<-·´¯`·. Codeproject.com: Visual C++ MVP

                        CPalliniC Online
                        CPalliniC Online
                        CPallini
                        wrote on last edited by
                        #31

                        Well, I'm a traditional-C lover: that fancy new C99 is alien to me. :laugh:

                        If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
                        This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

                        In testa che avete, signor di Ceprano?

                        J 1 Reply Last reply
                        0
                        • CPalliniC CPallini

                          Well, I'm a traditional-C lover: that fancy new C99 is alien to me. :laugh:

                          If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
                          This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke

                          J Offline
                          J Offline
                          Jhony george
                          wrote on last edited by
                          #32

                          Thanks for ur kind reply to all members whoever particpated in the discussion., by, Manivannan@Congruent

                          Born to win...!

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