C Programming (Turbo C++ Compiler) - Static Global Variables

---

Variables can be declared in stack or heap or static. Static variables means the memory is allocated statically and its life time is throughout the program execution time.

If a variable is allocated on the stack, we can see that stack size is increasing. If a variable is allocated on the heap (example malloc in C), we can see that heap size if increasing.

If I allocate a variable of 100 KB in static, which size will increase? Stack or Heap? Both are not correct. Your size of the .EXE file will increase..! This might be a surprise to many programmers in the begining. Similarly global variables are also allocated like static variables and its life time is throughout the program execution time.

IsEntered is a static global variable and can be used by any function defined in the file.

Source Code

---

#include <stdio.h>

 

static int IsEntered = -1;

 

void DisplayStatus()

{

    if(IsEntered == 1)

        printf("Function Enters\n");

    else if(IsEntered == 2)

        printf("Function Exits\n");

    else

        printf("Not initialized\n");

}

 

void EnterFunction()

{

    IsEntered = 1;

}

 

void ExitFunction()

{

    IsEntered = 2;

}

 

int main()

{

    DisplayStatus();

    EnterFunction();

    DisplayStatus();

    ExitFunction();

    DisplayStatus();

 

    return 0;

}

Output

---

Not initialized

Function Enters

Function Exits

---

---