Static and Local Scope

Someone says, "I just want to define a int var in a. h file. Who PA?

Now we see the following example.

Static:local in You

---------------ah.h-----------------

static int a=1;

------------------------------

----------------Callseta.cpp--------------

#include "ah.h"

#include <iostream>

using namespace Std;

void Seta ()

{

a=2;

cout<< "Call Seta ()" <<endl;

cout<< "in Call, A=" <<a<<endl;

}

--------------------------------------------

-----------------main.cpp---------------

#include "ah.h"

#include <iostream>

extern void Seta ();

using namespace Std;

void Main ()

{

cout<< "A=" <<a<<endl;

Seta ();

cout<< "After Seta ()" <<endl;

cout<< "A=" <<a<<endl;

}

-----------------------------------

Output:

A=1
Call Seta ()
In Call, a=2
After Seta ()
A=1
Please press any key to continue ...

----------------------------------

This is the local in main.cpp. For include "", the A is static.

So there is "int a", one in Main.cpp's scope or workspace, the other in Callseta.cpp ' s scope.

They is, different int Var, with different address allocated.

They only live in their own. Any of the guy outside can isn't see her beauty.

Interesting things is:

When your call Seta () is main.cpp, the pointer turns to the program space of Callseta.cpp.

It isn't realized that firstly clone of the program to the MAIN.CPP's program data segament.

The pointer turns onto the orginal and the only one program data segament of Seta () in Callseta.cpp.

So in this scope, a means his A, not the A in main, and which is amazing.

Static and Local Scope