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Phlip
Guest
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 Posted: Sat Sep 27, 2003 6:12 pm Post subject: Re: void ErrorMessage(int,int) const |
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Gary wrote:
| Quote: | I read the prototype as:
return type is void, function name is ErrorMessage.
The parameters are unusual, I don't know how to refer to those
unreferenced parameters.
|
Are you writing the function or calling it?
| Quote: | As for const, does that mean that the function is unchangeable?
|
Were that function a member of a class, the secret 'this' pointer would
point to a constant object. That means you can't change any members of the
object, or call any member function that is not 'const'.
I cross-posted to the newsgroup where this question belongs.
--
Phlip
http://www.c2.com/cgi/wiki?TestFirstUserInterfaces
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Jack Klein
Guest
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| Posted: Sun Sep 28, 2003 2:11 am Post subject: Re: void ErrorMessage(int,int) const |
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On Sat, 27 Sep 2003 18:12:12 GMT, "Phlip" <phlip_cpp (AT) yahoo (DOT) com> wrote
in comp.programming:
| Quote: | Gary wrote:
I read the prototype as:
return type is void, function name is ErrorMessage.
The parameters are unusual, I don't know how to refer to those
unreferenced parameters.
Are you writing the function or calling it?
As for const, does that mean that the function is unchangeable?
Were that function a member of a class, the secret 'this' pointer would
point to a constant object. That means you can't change any members of the
object, or call any member function that is not 'const'.
I cross-posted to the newsgroup where this question belongs.
|
It's not a secret, honest. Everybody programming in C++ for more than
a week or so knows it's there.
--
Jack Klein
Home: http://JK-Technology.Com
FAQs for
comp.lang.c http://www.eskimo.com/~scs/C-faq/top.html
comp.lang.c++ http://www.parashift.com/c++-faq-lite/
alt.comp.lang.learn.c-c++ ftp://snurse-l.org/pub/acllc-c++/faq
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Gary
Guest
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| Posted: Sun Sep 28, 2003 2:04 pm Post subject: Re: void ErrorMessage(int,int) const |
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Jack Klein <jackklein (AT) spamcop (DOT) net> wrote
| Quote: | On Sat, 27 Sep 2003 18:12:12 GMT, "Phlip" <phlip_cpp (AT) yahoo (DOT) com> wrote
in comp.programming:
Gary wrote:
I read the prototype as:
return type is void, function name is ErrorMessage.
The parameters are unusual, I don't know how to refer to those
unreferenced parameters.
Are you writing the function or calling it?
As for const, does that mean that the function is unchangeable?
Were that function a member of a class, the secret 'this' pointer would
point to a constant object. That means you can't change any members of the
object, or call any member function that is not 'const'.
I cross-posted to the newsgroup where this question belongs.
It's not a secret, honest. Everybody programming in C++ for more than
a week or so knows it's there.
|
I'm writing the function. A prototype was provided, and I need to
figure out to reference the parameters. Until now, I thought you
requried variable names, but I'm hoping there's another way.
Regards.
Gary
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Mike Wahler
Guest
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| Posted: Sun Sep 28, 2003 4:59 pm Post subject: Re: void ErrorMessage(int,int) const |
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"Gary" <gjc888 (AT) hotmail (DOT) com> wrote
| Quote: | Jack Klein <jackklein (AT) spamcop (DOT) net> wrote
On Sat, 27 Sep 2003 18:12:12 GMT, "Phlip" <phlip_cpp (AT) yahoo (DOT) com> wrote
in comp.programming:
Gary wrote:
I read the prototype as:
return type is void, function name is ErrorMessage.
The parameters are unusual, I don't know how to refer to those
unreferenced parameters.
Are you writing the function or calling it?
As for const, does that mean that the function is unchangeable?
Were that function a member of a class, the secret 'this' pointer
would
point to a constant object. That means you can't change any members of
the
object, or call any member function that is not 'const'.
I cross-posted to the newsgroup where this question belongs.
It's not a secret, honest. Everybody programming in C++ for more than
a week or so knows it's there.
I'm writing the function. A prototype was provided, and I need to
figure out to reference the parameters. Until now, I thought you
requried variable names, but I'm hoping there's another way.
|
A prototype only needs the type names, but many folks
add identifiers as well for documentation purposes.
In a function, if you want to refer to the parameters
then of course they'll need identifiers.
Why do you "hope there's another way"? What prevents
you from giving identifiers to your paramters?
int foo(int, int); // prototype
int foo(int arg1, int )
{
cout << arg1;
// cant get at second arg, no identifier
}
-Mike
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Joe Wright
Guest
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| Posted: Sun Sep 28, 2003 5:16 pm Post subject: Re: void ErrorMessage(int,int) const |
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Gary wrote:
| Quote: |
Jack Klein <jackklein (AT) spamcop (DOT) net> wrote
On Sat, 27 Sep 2003 18:12:12 GMT, "Phlip" <phlip_cpp (AT) yahoo (DOT) com> wrote
in comp.programming:
Gary wrote:
I read the prototype as:
return type is void, function name is ErrorMessage.
The parameters are unusual, I don't know how to refer to those
unreferenced parameters.
Are you writing the function or calling it?
As for const, does that mean that the function is unchangeable?
Were that function a member of a class, the secret 'this' pointer would
point to a constant object. That means you can't change any members of the
object, or call any member function that is not 'const'.
I cross-posted to the newsgroup where this question belongs.
It's not a secret, honest. Everybody programming in C++ for more than
a week or so knows it's there.
I'm writing the function. A prototype was provided, and I need to
figure out to reference the parameters. Until now, I thought you
requried variable names, but I'm hoping there's another way.
Regards.
Gary
|
The function itself requires named parameters but the prototype doesn't
care. It only needs the type or the parameters. Naming parameters in
prototypes is only a clue to the reader, not the compiler, about what
the parameter might be.
The reason for the prototype is to 'warn' the compiler that you plan to
call a particular function so that the compiler might check that you
call the function correctly and perhaps even convert the type of your
given parameter to the type the function expects. For example, when you
include math.h you get a prototype for the pow function which looks
something like..
double pow(double _x, double _y); /* names of the parameters are not
required */
In your program you might have something like..
int p;
p = pow(2,3);
...and the compiler knows how to handle everything and p == 8.
--
Joe Wright mailto:joewwright (AT) earthlink (DOT) net
"Everything should be made as simple as possible, but not simpler."
--- Albert Einstein ---
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Kevin Goodsell
Guest
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| Posted: Sun Sep 28, 2003 6:37 pm Post subject: Re: void ErrorMessage(int,int) const |
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Joe Wright wrote:
| Quote: | Gary wrote:
I'm writing the function. A prototype was provided, and I need to
figure out to reference the parameters. Until now, I thought you
requried variable names, but I'm hoping there's another way.
Regards.
Gary
The function itself requires named parameters
|
Well, only if you want to use them. You're free to leave off the names,
but then you have no way to refer to the parameter.
-Kevin
--
My email address is valid, but changes periodically.
To contact me please use the address from a recent posting.
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Gary
Guest
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| Posted: Sun Sep 28, 2003 10:34 pm Post subject: Re: void ErrorMessage(int,int) const |
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Joe Wright <joewwright (AT) earthlink (DOT) net> wrote
| Quote: | Gary wrote:
Jack Klein <jackklein (AT) spamcop (DOT) net> wrote
On Sat, 27 Sep 2003 18:12:12 GMT, "Phlip" <phlip_cpp (AT) yahoo (DOT) com> wrote
in comp.programming:
Gary wrote:
I read the prototype as:
return type is void, function name is ErrorMessage.
The parameters are unusual, I don't know how to refer to those
unreferenced parameters.
Are you writing the function or calling it?
As for const, does that mean that the function is unchangeable?
Were that function a member of a class, the secret 'this' pointer would
point to a constant object. That means you can't change any members of the
object, or call any member function that is not 'const'.
I cross-posted to the newsgroup where this question belongs.
It's not a secret, honest. Everybody programming in C++ for more than
a week or so knows it's there.
I'm writing the function. A prototype was provided, and I need to
figure out to reference the parameters. Until now, I thought you
requried variable names, but I'm hoping there's another way.
Regards.
Gary
The function itself requires named parameters but the prototype doesn't
care. It only needs the type or the parameters. Naming parameters in
prototypes is only a clue to the reader, not the compiler, about what
the parameter might be.
The reason for the prototype is to 'warn' the compiler that you plan to
call a particular function so that the compiler might check that you
call the function correctly and perhaps even convert the type of your
given parameter to the type the function expects. For example, when you
include math.h you get a prototype for the pow function which looks
something like..
double pow(double _x, double _y); /* names of the parameters are not
required */
In your program you might have something like..
int p;
p = pow(2,3);
..and the compiler knows how to handle everything and p == 8.
|
Thank you for your prompt response.
I agree that calling the function, or writing the prototype, and
passing the parameters do not require the name of the parameter.
However, I'm writing the function. Is it possible to write a function
body without having parameter names?
Regards. Gary
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Gary
Guest
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| Posted: Sun Sep 28, 2003 10:36 pm Post subject: Re: void ErrorMessage(int,int) const |
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Kevin Goodsell <usenet1.spamfree.fusion (AT) neverbox (DOT) com> wrote
| Quote: | Joe Wright wrote:
Gary wrote:
I'm writing the function. A prototype was provided, and I need to
figure out to reference the parameters. Until now, I thought you
requried variable names, but I'm hoping there's another way.
Regards.
Gary
The function itself requires named parameters
Well, only if you want to use them. You're free to leave off the names,
but then you have no way to refer to the parameter.
-Kevin
|
So no way at all huh? Not even with function pointers ?
Regards.
Gary
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Mike Wahler
Guest
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| Posted: Sun Sep 28, 2003 10:42 pm Post subject: Re: void ErrorMessage(int,int) const |
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"Gary" <gjc888 (AT) hotmail (DOT) com> wrote
| Quote: | Joe Wright <joewwright (AT) earthlink (DOT) net> wrote
Gary wrote:
Jack Klein <jackklein (AT) spamcop (DOT) net> wrote
On Sat, 27 Sep 2003 18:12:12 GMT, "Phlip"
wrote
in comp.programming:
Gary wrote:
I read the prototype as:
return type is void, function name is ErrorMessage.
The parameters are unusual, I don't know how to refer to those
unreferenced parameters.
Are you writing the function or calling it?
As for const, does that mean that the function is unchangeable?
Were that function a member of a class, the secret 'this' pointer
would
point to a constant object. That means you can't change any
members of the
object, or call any member function that is not 'const'.
I cross-posted to the newsgroup where this question belongs.
It's not a secret, honest. Everybody programming in C++ for more
than
a week or so knows it's there.
I'm writing the function. A prototype was provided, and I need to
figure out to reference the parameters. Until now, I thought you
requried variable names, but I'm hoping there's another way.
Regards.
Gary
The function itself requires named parameters but the prototype doesn't
care. It only needs the type or the parameters. Naming parameters in
prototypes is only a clue to the reader, not the compiler, about what
the parameter might be.
The reason for the prototype is to 'warn' the compiler that you plan to
call a particular function so that the compiler might check that you
call the function correctly and perhaps even convert the type of your
given parameter to the type the function expects. For example, when you
include math.h you get a prototype for the pow function which looks
something like..
double pow(double _x, double _y); /* names of the parameters are not
required */
In your program you might have something like..
int p;
p = pow(2,3);
..and the compiler knows how to handle everything and p == 8.
Thank you for your prompt response.
I agree that calling the function, or writing the prototype, and
passing the parameters do not require the name of the parameter.
However, I'm writing the function. Is it possible to write a function
body without having parameter names?
|
Of course, but your function will not have
access to them.
-Mike
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Mike Wahler
Guest
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| Posted: Sun Sep 28, 2003 10:44 pm Post subject: Re: void ErrorMessage(int,int) const |
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"Gary" <gjc888 (AT) hotmail (DOT) com> wrote
| Quote: | Kevin Goodsell <usenet1.spamfree.fusion (AT) neverbox (DOT) com> wrote
Joe Wright wrote:
Gary wrote:
I'm writing the function. A prototype was provided, and I need to
figure out to reference the parameters. Until now, I thought you
requried variable names, but I'm hoping there's another way.
Regards.
Gary
The function itself requires named parameters
Well, only if you want to use them. You're free to leave off the names,
but then you have no way to refer to the parameter.
-Kevin
So no way at all huh?
|
No. Why do you want/need to do that?
| Quote: | Not even with function pointers ?
|
A 'function pointer' is a pointer to a function.
You can invoke a function via a function pointer,
but that does not do anything 'special' with
its parameters.
-Mike
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Kevin Goodsell
Guest
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| Posted: Mon Sep 29, 2003 12:19 am Post subject: Re: void ErrorMessage(int,int) const |
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Gary wrote:
| Quote: |
Thank you for your prompt response.
|
Please trim when replying. No need to quote hundreds of lines of
irrelevant text.
| Quote: | I agree that calling the function, or writing the prototype, and
passing the parameters do not require the name of the parameter.
However, I'm writing the function. Is it possible to write a function
body without having parameter names?
|
You don't have to give names to the parameters, but names are the only
way of referring to the parameters, so if you give no names you have no
access:
void foo(int)
{
cout << "This is foo. But I don't know what"
"value you passed to me." << endl;
}
Your situation is puzzling. Why would you not want to give your
parameters names?
-Kevin
--
My email address is valid, but changes periodically.
To contact me please use the address from a recent posting.
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