Storage Classes(in a single file)

#include <stdio.h>

int g = 0;

extern int k;

void fun(char c);

main()

{

char c ='A';

auto int i;

++g;

fun(c);

++g;

fun(c+1);

fun(c+2);

}

void fun(char c)

{

int y = 3;

static int x=0;

putchar(c);

printf(" x=%d, y=%d, g=%d\n",

x++, y--, ++g);

}

A x=0, y=3, g=2

B x=1, y=3, g=4

C x=2, y=3, g=5

g and k have storage class "extern". g and k are global variables, visible to all functions, exist during whole program execution.

c and i are storage class "auto". c and i are local to main() only, exist only when main() exists.

x has storage class "static". x is local to fun(), known only in fun(). x is initialized once, exists during the whole program. y is local, storage class "auto", initialized every time when fun() is evoked, and exists only when fun() is active.

Print out.

This is program pg390.c

Previous slide

Next slide

Back to first slide

View graphic version