need some class help
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From: Joseph M. Newcomer on 20 Feb 2010 11:47 See below... On Sat, 20 Feb 2010 09:08:09 -0500, "RB" <NoMail(a)NoSpam> wrote: >Congratulations on your MVP award and >thank you for the very extensive and detailed reply. >So in summation: >A SuperClass is a base class **** No, you didn't read carefully. A superclass is a class from which another class is derived. A base class is typically a class which is NOT derived from any other class. If I have the relationship A->B->C then A is a base class A is a superclass of B A is a superclass of C B is a subclass of A B is a superclass of C C is a subclass of B C is a subclass of A I would not call B a "base class". ***** >and aSubClass is a derived class >and a nested class is a Class inside of another class >If I read your reply correctly these are just new words for old things > >And as to the MFC control category variable: > >>"Joseph M. Newcomer" wrote in message >> The type is DerivedClass. The variable is an instance of DerivedClass. >>The variable is a member of the FormViewClass. >> **** > >(please correct me if I misunderstood you ) >So ..... the control category variable actually creates an instance of a Class object >of the type ( DerivedClass ) ? **** Yes. If I write DerivedClass X; then X is an instance of the class DerivedClass. Note that being an instance of a class does not mean there is a window associated with the variable. Only later will the HWND be created and attached to the object. **** > (or the control Base class if you did not use a derived one) >This is kinda what I felt it was doing in my gut, and is why I named it >" m_FormListBoxObj " or is my gut still leading me to misunderstand your reply? **** Yes, it is an instance of the object; What name you choose is based on your favorite naming conventions. But it does represent an object instance. joe **** > >>"Joseph M. Newcomer" wrote in message >>>#include "DerivedClass.h" // docs said to add the derived class include here and in fact it >>> // does not work without it, but causes sbrowser to act strange >> **** >> I wouldn't trust the browser as far as I could throw it. The declaration of the #include >> is essential. if the browser acts strange, that is a bug. Report it. > >Ok I'm glad I do have that right since the sbrowser was making feel I had done something >wrong. The sbrowser has always performed as expected in the past, I'm not sure reporting >a bug would do any good since I use Visual C Pro. ver 6.0 which I doubt if they write fixes >for it anymore. I did all the updates for it already. It has served me well over the years for >what I do. > >and also > >>"Joseph M. Newcomer" wrote in message >> I tend to assume that if Intellinonsense says something that makes no sense, >> < cut out >So I wouldn't place much reliance on what it says. >> >> The variable DerivedClass is a member of the FormViewClass, but you have not indicated >> what class the DerivedClass is derived from. So I don't know how to interpret the output. > >DerivedClass was from the base class of CListBox and so then .... > >> All you have is (reduced to essentials): >> class DerivedClass : public SomeOtherClass {...}; >> class FormViewClass : public CFormView { >> DerivedClass m_FormListBoxObj; > >Well if the DerivedClass is a member of the FormViewClass then ...... >Am I correct in ascertaining that the DerivedClass is nested inside of my FormViewClass ? >so that in C++ it would be like FormViewClass : DerivedClass : m_FormListBoxObj ? > >I thank you again, and even if I misunderstood some of your excellent answers I believe >I am of a better understanding and will now go back and read some bibliographies over >again. RB > Joseph M. Newcomer [MVP] email: newcomer(a)flounder.com Web: http://www.flounder.com MVP Tips: http://www.flounder.com/mvp_tips.htm
From: RB on 20 Feb 2010 18:47 Oh ok , got it this time, the whole superclass and subclass thing is a replacement for what I learned as Parent class and child class. But a Base class must be created of it's own without any derived class input. Thanks. "Joseph M. Newcomer" <newcomer(a)flounder.com> wrote in message news:v440o5lct6bc5j64mre24brbqh2c1gsqcb(a)4ax.com... > See below... > On Sat, 20 Feb 2010 09:08:09 -0500, "RB" <NoMail(a)NoSpam> wrote: > >>Congratulations on your MVP award and >>thank you for the very extensive and detailed reply. >>So in summation: >>A SuperClass is a base class > **** > No, you didn't read carefully. A superclass is a class from which another class is > derived. A base class is typically a class which is NOT derived from any other class. > > If I have the relationship > A->B->C > > then > A is a base class > A is a superclass of B > A is a superclass of C > > B is a subclass of A > B is a superclass of C > > C is a subclass of B > C is a subclass of A > > I would not call B a "base class". > ***** >>and aSubClass is a derived class >>and a nested class is a Class inside of another class >>If I read your reply correctly these are just new words for old things >> >>And as to the MFC control category variable: >> >>>"Joseph M. Newcomer" wrote in message >>> The type is DerivedClass. The variable is an instance of DerivedClass. >>>The variable is a member of the FormViewClass. >>> **** >> >>(please correct me if I misunderstood you ) >>So ..... the control category variable actually creates an instance of a Class object >>of the type ( DerivedClass ) ? > **** > Yes. If I write > DerivedClass X; > then X is an instance of the class DerivedClass. Note that being an instance of a class > does not mean there is a window associated with the variable. Only later will the HWND be > created and attached to the object. > **** >> (or the control Base class if you did not use a derived one) >>This is kinda what I felt it was doing in my gut, and is why I named it >>" m_FormListBoxObj " or is my gut still leading me to misunderstand your reply? > **** > Yes, it is an instance of the object; What name you choose is based on your favorite > naming conventions. But it does represent an object instance. > joe > **** >> >>>"Joseph M. Newcomer" wrote in message >>>>#include "DerivedClass.h" // docs said to add the derived class include here and in fact it >>>> // does not work without it, but causes sbrowser to act strange >>> **** >>> I wouldn't trust the browser as far as I could throw it. The declaration of the #include >>> is essential. if the browser acts strange, that is a bug. Report it. >> >>Ok I'm glad I do have that right since the sbrowser was making feel I had done something >>wrong. The sbrowser has always performed as expected in the past, I'm not sure reporting >>a bug would do any good since I use Visual C Pro. ver 6.0 which I doubt if they write fixes >>for it anymore. I did all the updates for it already. It has served me well over the years for >>what I do. >> >>and also >> >>>"Joseph M. Newcomer" wrote in message >>> I tend to assume that if Intellinonsense says something that makes no sense, >>> < cut out >So I wouldn't place much reliance on what it says. >>> >>> The variable DerivedClass is a member of the FormViewClass, but you have not indicated >>> what class the DerivedClass is derived from. So I don't know how to interpret the output. >> >>DerivedClass was from the base class of CListBox and so then .... >> >>> All you have is (reduced to essentials): >>> class DerivedClass : public SomeOtherClass {...}; >>> class FormViewClass : public CFormView { >>> DerivedClass m_FormListBoxObj; >> >>Well if the DerivedClass is a member of the FormViewClass then ...... >>Am I correct in ascertaining that the DerivedClass is nested inside of my FormViewClass ? >>so that in C++ it would be like FormViewClass : DerivedClass : m_FormListBoxObj ? >> >>I thank you again, and even if I misunderstood some of your excellent answers I believe >>I am of a better understanding and will now go back and read some bibliographies over >>again. RB >> > Joseph M. Newcomer [MVP] > email: newcomer(a)flounder.com > Web: http://www.flounder.com > MVP Tips: http://www.flounder.com/mvp_tips.htm
From: Joseph M. Newcomer on 20 Feb 2010 22:51
The superclass/subclass is parent/child. Generally, we use the term "base class" to refer to a class that is not derived from any other class. But the ClassWizard in VS will talk about adding a class and ask you to designate a "base class", and will give options like CStatic, which is really a subclass of CWnd, which is a subclass of CCmdTarget, which is a subclass of CObject, which is the actual "base" class not derived from anything. So the term is a bit looser in its definition. joe On Sat, 20 Feb 2010 18:47:54 -0500, "RB" <NoMail(a)NoSpam> wrote: >Oh ok , got it this time, the whole superclass and subclass thing is a replacement >for what I learned as Parent class and child class. But a Base class must be created >of it's own without any derived class input. >Thanks. > >"Joseph M. Newcomer" <newcomer(a)flounder.com> wrote in message news:v440o5lct6bc5j64mre24brbqh2c1gsqcb(a)4ax.com... >> See below... >> On Sat, 20 Feb 2010 09:08:09 -0500, "RB" <NoMail(a)NoSpam> wrote: >> >>>Congratulations on your MVP award and >>>thank you for the very extensive and detailed reply. >>>So in summation: >>>A SuperClass is a base class >> **** >> No, you didn't read carefully. A superclass is a class from which another class is >> derived. A base class is typically a class which is NOT derived from any other class. >> >> If I have the relationship >> A->B->C >> >> then >> A is a base class >> A is a superclass of B >> A is a superclass of C >> >> B is a subclass of A >> B is a superclass of C >> >> C is a subclass of B >> C is a subclass of A >> >> I would not call B a "base class". >> ***** >>>and aSubClass is a derived class >>>and a nested class is a Class inside of another class >>>If I read your reply correctly these are just new words for old things >>> >>>And as to the MFC control category variable: >>> >>>>"Joseph M. Newcomer" wrote in message >>>> The type is DerivedClass. The variable is an instance of DerivedClass. >>>>The variable is a member of the FormViewClass. >>>> **** >>> >>>(please correct me if I misunderstood you ) >>>So ..... the control category variable actually creates an instance of a Class object >>>of the type ( DerivedClass ) ? >> **** >> Yes. If I write >> DerivedClass X; >> then X is an instance of the class DerivedClass. Note that being an instance of a class >> does not mean there is a window associated with the variable. Only later will the HWND be >> created and attached to the object. >> **** >>> (or the control Base class if you did not use a derived one) >>>This is kinda what I felt it was doing in my gut, and is why I named it >>>" m_FormListBoxObj " or is my gut still leading me to misunderstand your reply? >> **** >> Yes, it is an instance of the object; What name you choose is based on your favorite >> naming conventions. But it does represent an object instance. >> joe >> **** >>> >>>>"Joseph M. Newcomer" wrote in message >>>>>#include "DerivedClass.h" // docs said to add the derived class include here and in fact it >>>>> // does not work without it, but causes sbrowser to act strange >>>> **** >>>> I wouldn't trust the browser as far as I could throw it. The declaration of the #include >>>> is essential. if the browser acts strange, that is a bug. Report it. >>> >>>Ok I'm glad I do have that right since the sbrowser was making feel I had done something >>>wrong. The sbrowser has always performed as expected in the past, I'm not sure reporting >>>a bug would do any good since I use Visual C Pro. ver 6.0 which I doubt if they write fixes >>>for it anymore. I did all the updates for it already. It has served me well over the years for >>>what I do. >>> >>>and also >>> >>>>"Joseph M. Newcomer" wrote in message >>>> I tend to assume that if Intellinonsense says something that makes no sense, >>>> < cut out >So I wouldn't place much reliance on what it says. >>>> >>>> The variable DerivedClass is a member of the FormViewClass, but you have not indicated >>>> what class the DerivedClass is derived from. So I don't know how to interpret the output. >>> >>>DerivedClass was from the base class of CListBox and so then .... >>> >>>> All you have is (reduced to essentials): >>>> class DerivedClass : public SomeOtherClass {...}; >>>> class FormViewClass : public CFormView { >>>> DerivedClass m_FormListBoxObj; >>> >>>Well if the DerivedClass is a member of the FormViewClass then ...... >>>Am I correct in ascertaining that the DerivedClass is nested inside of my FormViewClass ? >>>so that in C++ it would be like FormViewClass : DerivedClass : m_FormListBoxObj ? >>> >>>I thank you again, and even if I misunderstood some of your excellent answers I believe >>>I am of a better understanding and will now go back and read some bibliographies over >>>again. RB >>> >> Joseph M. Newcomer [MVP] >> email: newcomer(a)flounder.com >> Web: http://www.flounder.com >> MVP Tips: http://www.flounder.com/mvp_tips.htm > Joseph M. Newcomer [MVP] email: newcomer(a)flounder.com Web: http://www.flounder.com MVP Tips: http://www.flounder.com/mvp_tips.htm |