0 Static Storage Class

The feature of a variable defined to have a static storage class are as follows :

A static variable is declared by using keyword static.
Syntax : static type var-name; or type static var-name;

Storage                                   :               Computer Memory

Scope                                     :                Local to the block in which variable is defined

Default Initial Value              :                Zero
Lifetime                                 :               Value of the variable persists between different function calls

The static storage class specifier can only be applied to the following names:

• Objects
• Functions
• Class members
• Anonymous unions

You cannot declare any of the following as static:

• Type declarations
• Function declarations within a block
• Function parameters

Example :

#include <stdio.h>

int increment(void) {
  static int i = 0;
  i++;
  return i;
}

int main(void) {
  int j;
  for (j = 0; j < 5; j++) {
    printf("Value of f(): %d\n", increment());
  }
  return 0;
}

Output:

Value of increment(): 1
Value of increment(): 2
Value of increment(): 3
Value of increment(): 4
Value of increment(): 5

This is Because i is a static variable, it is not reinitialized to 0 on successive calls to increment().