scope.c

c版本的

                                          /* Chapter 5 - Program 4 */
#include "stdio.h"      /* Prototypes for Input/Output             */
void head1(void);       /* Prototype for head1                     */
void head2(void);       /* Prototype for head2                     */
void head3(void);       /* Prototype for head3                     */

int count;              /* This is a global variable               */

main()
{
register int index; /* This variable is available only in main */

   head1();
   head2();
   head3();
                      /* main "for" loop of this program */
   for (index = 8;index > 0;index--) {
      int stuff;  /* This variable is only available in these braces*/
      for (stuff = 0;stuff <= 6;stuff++)
         printf("%d ",stuff);
      printf(" index is now %d\n",index);
    }
}

int counter;      /* This is available from this point on */
void head1(void)
{
int index;        /* This variable is available only in head1 */

   index = 23;
   printf("The header1 value is %d\n",index);
}

void head2(void)
{
int count;  /* This variable is available only in head2 */
            /* and it displaces the global of the same name */

   count = 53;
   printf("The header2 value is %d\n",count);
   counter = 77;
}

void head3(void)
{
   printf("The header3 value is %d\n",counter);
}