calling a static function

[David Crow]

Not necessarily.

"Love people and use things, not love things and use people." - Unknown

"The brick walls are there for a reason...to stop the people who don't want it badly enough." - Randy Pausch

[steph5]

Hi I was in the understanding that if you declare a static function it can only be called from the source file where it is declared. Am I missing something?? The error says "unresolved external symbol" the call to the function is in file1.cpp where I have: myClass::myFunction(variable1, variable2); In myClass.h I have: class myClass { static void myFunction } and in myClass.cpp I have the function definition: myClass::myFunction() { //function definition } I can't call myFunction from file1.cpp As you can tell I am a novice programmer and in desperate need of explanation :(

[Mark Salsbery]

toxcct wrote:

not a native english speaker (like you)

LOL! I'm pretty sure the rest of the world doesn't call what we Americans speak "English" ;P

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Mark Salsbery]

Now that DavidCrow mentions it, and the caffeine is kicking in... I'm pretty sure I was right ;P LMAO

Mark Salsbery Microsoft MVP - Visual C++ :java:

[CPallini]

Nope. ;)

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
[My articles]

[Mark Salsbery]

steph5 wrote:

I was in the understanding that if you declare a static function it can only be called from the source file where it is declared. Am I missing something??

Yes :) That would make calling any external functions impossible.

steph5 wrote:

I can't call myFunction from file1.cpp

The linker can't find myClass.obj. Is myClass.cpp not part of the project? Mark

Mark Salsbery Microsoft MVP - Visual C++ :java:

[CPallini]

steph5 wrote:

I was in the understanding that if you declare a static function it can only be called from the source file where it is declared.

That's true.

steph5 wrote:

Am I missing something??

Yes: in

steph5 wrote:

class myClass { static void myFunction }

is not an ordinary (i.e. C-style) static function, is a static method (i.e is a member of the class even if you don't need an instance of the class to call it). :)

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
[My articles]

[Mark Salsbery]

CPallini wrote:

That's true.

Huh? I call static methods that aren't in the same source file all the time :)

Mark Salsbery Microsoft MVP - Visual C++ :java:

[steph5]

Any ideas how I can have a function I can call from anywhere but where I don't need an instance of the class to call it?

[Mark Salsbery]

You can call a static method of a class from other cpp files! You need to link the files however. The problem is in your project - the linker isn't finding the file with the function being called. Fix that and it will work. The two files in your example ARE in the same project, right?

Mark Salsbery Microsoft MVP - Visual C++ :java:

[steph5]

how?

[Mark Salsbery]

////////////////////////////
// myClass.h
////////////////////////////

class myClass
{
public:
static void StaticMethod();
};

////////////////////////////
// myClass.cpp
////////////////////////////

void myClass::StaticMethod()
{
}

////////////////////////////
// someother.cpp
////////////////////////////

void somefunc()
{
myClass::StaticMethod();
}

Maybe you forgot the part in red above...

Mark Salsbery Microsoft MVP - Visual C++ :java:

[steph5]

yes all the files are incluceded in the same project. how do I make sure the linker finds the file? The thing is I can call myClass::myFunction() from one of the .cpp files in the project, but I can't call it from another .cpp file in the same project. whats going on? Thanks for your time

[toxcct]

you're saying this as if such construction never exists... but I'm sure it is ! for example, the following is perfectly valid : "If I were you, I wouldn't do that"... ;P

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[john john mackey]

touché :laugh:

[Mark Salsbery]

Hey tox (aka Grammar Nazi)... Shouldn't you be busy working on this?[^] ;P

Mark Salsbery Microsoft MVP - Visual C++ :java:

[CPallini]

Actually his sentence,

steph5 wrote:

I was in the understanding that if you declare a static function it can only be called from the source file where it is declared.

and yours

Mark Salsbery wrote:

Huh? I call static methods that aren't in the same source file all the time

are not in conflict: standard (i.e C-like, not belonging to a class) static functions have file scope, while static methods have not such a constraint. :)

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
[My articles]

[toxcct]

Mark, wait. I didn't say all I write is gramatically correct; I make mistakes sometimes. BUT, isn't the construction I just asked you in this thread valid ?

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[toxcct]

CPallini wrote:

while static methods

C++ (actually Bjarne Stroustrup) don't talk about methods (which is more correct to Java/C#), but talks about member variables and member functions.

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[Mark Salsbery]

I'm just goofin with you here, of course.

toxcct wrote:

isn't the construction I just asked you in this thread valid ?

Where at? I missed something somewhere :)

Mark Salsbery Microsoft MVP - Visual C++ :java: