1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 | #include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
// okay to copy/adapt these two macros
#define log_int(n) printf("%s == %d\n", (#n), n)
#define log_addr(n) printf("%s == %p\n", (#n), (void*)n)
int main(int argc, char* argv[]) {
// variable
int n1 = 5;
// & gets address of a variable
int* a_n1 = &n1;
//printf("a_n1 == %p\n", (void*)a_n1);
log_addr(&n1);
log_addr(a_n1);
// get the value from the address a_n
int n2 = *a_n1;
log_int(n2);
log_int(*a_n1);
*a_n1 = 7;
log_int(*a_n1);
log_int(n1);
log_int(n2);
// this is probably counfusing with our naming conventons,
// but is valid
a_n1 = &n2;
log_int(*a_n1);
log_int(n1);
// this is "valid", but almost never useful
// in this case, causes a segfault
//a_n1 = (int*)5; // good example of when *not* to use casts
//log_int(*a_n1);
return EXIT_SUCCESS;
}
/* vim: set tabstop=4 shiftwidth=4 fileencoding=utf-8 noexpandtab: */
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