UMBC CMSC 201 Spring '02

An Example

The Program

/********************************************* ** File: pointers.c ** Author: S. Bogar ** Date: 1/3/77 ** Section: 101 ** SSN: 123-45-6789 ** EMail: bogar@cs.umbc.edu ** ** A simple program that uses pointers. **********************************************/ #include <stdio.h> int main () { int a = 1, b = 2; /* pointer declarations */ int *ptr1, *ptr2 ; ptr1 = &a ; printf("a = %d, &a = %p, ptr1 = %p, *ptr1 = %d\n", a, &a, ptr1, *ptr1) ; ptr1 = &b ; printf("b = %d, &b = %p, ptr1 = %p, *ptr1 = %d\n", b, &b, ptr1, *ptr1) ; *ptr1 = 35 ; printf("b = %d, &b = %p, ptr1 = %p, *ptr1 = %d\n", b, &b, ptr1, *ptr1) ; ptr2 = ptr1 ; *ptr2 = 17 ; printf("b = %d, &b = %p, ptr1 = %p, *ptr1 = %d\n", b, &b, ptr1, *ptr1) ; return 0; }

Output

linux1[75] % gcc -Wall -ansi pointers.c linux1[76] % a.out a = 1, &a = 0x7ffffa94, ptr1 = 0x7ffffa94, *ptr1 = 1 b = 2, &b = 0x7ffffa90, ptr1 = 0x7ffffa90, *ptr1 = 2 b = 35, &b = 0x7ffffa90, ptr1 = 0x7ffffa90, *ptr1 = 35 b = 17, &b = 0x7ffffa90, ptr1 = 0x7ffffa90, *ptr1 = 17 linux1[77] %

Thursday, 17-Jan-2002 13:52:22 EST