Static Storage Class in C (Keyword)

Local Implementation of Static Storage Class

• When a static Specifier is applied to function or block the compiler create permanent storage for it.
• Static Local variable remains visible only to the function or block in which it is defined.
• A Static Local variables is a local variable that retains its value between functions calls.

Code

#include 
void demo()
{
    static int i = 1;
    {
        static int i;
        printf("%d ",i);
        i++;
    }
    printf("%d\n",i);
    i++;
}

int main()
{
   demo();
   demo();
}

Output

0 1
1 2

Global Implementation of Static Storage Class

• When static specifier is applied to a global variable or a function then compiler makes that variable or function known only to the file in which it is defined.
• A static global variable is a global variable with internal linkage.
• That means even the variable is global but other files are not having any knowledge of it.
• Other file cannot access or alter it’s content directly.

Code

#include 
void func_1();
int a, b = 10;
int main()
{
    func_1();
    func_1();
    return 0;
}

void func_1()
{
    int a = 1;
    static int b = 100;
   printf("a = %d\n", a);
    printf("b = %d\n\n", b);
    a++;
    b++;
}

Output

a = 1
b = 100

a = 1
b = 10