Hi,
I could understand the difference between class and object. However, I
could find out a good definiton of type. how to understand the
relaitonship between type, class, and object? Thanks!
Michael
7  1960 
Michael wrote:
I could understand the difference between class and object. However, I
could find out a good definiton of type. how to understand the
relaitonship between type, class, and object? Thanks!
'class' is a user-defined type (UDT, a very common TLA in OOP). A type
is a "kind" of objects, definiting common traits of all *instances* of
that type ("objects"). Types in C++ are characterized by the name and
the *definition*. Types in C++ consist of built-in and user-defined.
The definition of a UDT contains *declarations*, which describe the
representation and the behaviour of the instances of the UDT. The
representation and the behaviour of built-in types is defined in the
Standard.
V
--
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I do not respond to top-posted replies, please don't ask
Victor Bazarov wrote:
'class' is a user-defined type (UDT, a very common TLA in OOP). A type
is a "kind" of objects, definiting common traits of all *instances* of
that type ("objects"). Types in C++ are characterized by the name and
the *definition*. Types in C++ consist of built-in and user-defined.
The definition of a UDT contains *declarations*, which describe the
representation and the behaviour of the instances of the UDT. The
representation and the behaviour of built-in types is defined in the
Standard.
Could you please take an example for me to better understand it?
Victor Bazarov wrote:
Michael wrote:
I could understand the difference between class and object. However, I
could find out a good definiton of type. how to understand the
relaitonship between type, class, and object? Thanks!
'class' is a user-defined type (UDT, a very common TLA in OOP). A type
is a "kind" of objects, definiting common traits of all *instances* of
that type ("objects"). Types in C++ are characterized by the name and
the *definition*. Types in C++ consist of built-in and user-defined.
The definition of a UDT contains *declarations*, which describe the
representation and the behaviour of the instances of the UDT. The
representation and the behaviour of built-in types is defined in the
Standard.
I would think of type as "Class". Is thar right? There is no difference
to call "Class" or "Type".
Michael wrote:
Hi,
I could understand the difference between class and object. However, I
could find out a good definiton of type. how to understand the
relaitonship between type, class, and object? Thanks!
Michael
Well, in C++ : the types *include* the classes and objects are instances
of classes. Some types that are not classes :
C-like types : int, char, float
Function pointers types : int (*)(int,int)
Method pointers types : int (MyClass::*)(in t,int)
Other pointers type : int*, MyClass*
Pierre
Michael wrote:
Victor Bazarov wrote:
>Michael wrote:
>>I could understand the difference between class and object.
However, I could find out a good definiton of type. how to
understand the relaitonship between type, class, and object? Thanks!
'class' is a user-defined type (UDT, a very common TLA in OOP). A
type is a "kind" of objects, definiting common traits of all
*instances* of that type ("objects"). Types in C++ are
characterize d by the name and the *definition*. Types in C++
consist of built-in and user-defined. The definition of a UDT
contains *declarations*, which describe the representation and the
behaviour of the instances of the UDT. The representation and the
behaviour of built-in types is defined in the Standard.
I would think of type as "Class". Is thar right?
No, in C++ it's vice-versa. Did you actually read what I posted?
Types consist of built-in and user-defined. "class" is a user-defined
type. So class is a type. A 'type' is a wider concept than a 'class',
at least in C++.
There is no
difference to call "Class" or "Type".
In some circumstances there is. You can derive from a class, you
cannot, generally speaking, derive from a type.
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
"Michael" <mi*******@gmai l.comwrote in message
news:11******** **************@ i3g2000cwc.goog legroups.com...
>
Victor Bazarov wrote:
>Michael wrote:
I could understand the difference between class and object. However, I
could find out a good definiton of type. how to understand the
relaitonship between type, class, and object? Thanks!
'class' is a user-defined type (UDT, a very common TLA in OOP). A type
is a "kind" of objects, definiting common traits of all *instances* of
that type ("objects"). Types in C++ are characterized by the name and
the *definition*. Types in C++ consist of built-in and user-defined.
The definition of a UDT contains *declarations*, which describe the
representati on and the behaviour of the instances of the UDT. The
representati on and the behaviour of built-in types is defined in the
Standard.
I would think of type as "Class". Is thar right? There is no difference
to call "Class" or "Type".
Where do you get the word "Class" from? Are you referring to the keyword
"class", which denotes one kind of user-defined-type? (The other being the
keyword "struct".)
The concept of "type" in C++ means, basically, "what kind of thing is
this?". So, some examples of types are: int, char, and unsigned long.
These are built-in types, already defined in the language for you.
If you have a class definition like this:
class MyClass { /* member stuff here */ };
....then you have a user-defined type (or UDT), whose type is MyClass.
Likewise, the definition
struct MyStruct { /* member stuff here */ };
....defines a UDT, whose type is MyStruct.
(Sometimes in OOP, the terms "UDT" and "class" are used interchangeably , but
to me that can be confusing, since in C++ we also have UDTs which are
struct's, as I've shown.)
Given the above definitions,
MyClass aMyClassInstanc e;
....declares a variable called aMyClassInstanc e, whose type is MyClass, and
MyStruct aMyStructInstan ce;
....declares a variable called aMyStructInstan ce, whose type is MyStruct, and
-Howard
Howard wrote:
>
"Michael" <mi*******@gmai l.comwrote in message
news:11******** **************@ i3g2000cwc.goog legroups.com...
I would think of type as "Class". Is thar right? There is no
difference to call "Class" or "Type".
Where do you get the word "Class" from? Are you referring to the
keyword "class", which denotes one kind of user-defined-type? (The
other being the keyword "struct".)
Poor ol' "union", forsaken again.
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