c programming

Question

Life of static variables span across function calls but their scope is respective to their function body only.

What is the meaning of this statement?

Comments

suppose there is a static variable in function A(), So this static variable cannot be called directly access from some other function

For example

A()

{

static int a=1;

a++

}

B()

{

a=a+1;

}

now B() cant call 'a' becoz its scope is in function A() only

but if we call function A() from function B() then it is valid and the value of 'a' will be incremented by 1 from it's last value

---

This may help you.

#include <stdio.h>
int main()
{
first();
second();
}

void first()
{
static int x;
x++;
printf("First of x: %d\n",x);
}

void second()
{
static int x;
x++;
printf("Second of x: %d\n",x);
}

Output:

First of x=1

Second of x=1

So what can we say about static variable  ?

Even though life of static variables span across function calls but their scope is respective to their function body only. So variable x of each function has separate copies whose life span across function calls.

Answer 1

Suppose ,there are two functions.

Sum0() and sum1(). An static variable is declared in function sum0; (i.e)

int  sum0(

{

static int a=0;// This statement executes during first function call.and for rest of four calls this statement don't executes.

a++;

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

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

return 0;

}

int Sum1()

{
-----------

-----------

 a++;// Here static variable a will not be visible in this function.i.e (scope of a static  variable  is limited to the function in which it is defined );

}

int main( )

{

  for(int i=0;i<5;i++)

     sum0();/*when this function is called  five times local static variable a is defined once i.ememory

                  is allocated once and value increments five times. After function returns last time,memory is

                   deallocated . (i.e) static variables span across function calls.

return 0;

}