version of ex16 with structs created on the stack, using dot syntax instead of ->, passing by value

This commit is contained in:
Dan Buch 2011-09-20 14:38:34 -04:00
parent 55fddaff46
commit 9d258d22b8

56
ex16.c
View File

@ -10,64 +10,36 @@ struct Person {
int weight; int weight;
}; };
struct Person *Person_create(char *name, int age, int height, int weight) void Person_print(struct Person who)
{ {
struct Person *who = malloc(sizeof(struct Person)); printf("Name: %s\n", who.name);
assert(who != NULL); printf("\tAge: %d\n", who.age);
printf("\tHeight: %d\n", who.height);
who->name = strdup(name); printf("\tWeight: %d\n", who.weight);
who->age = age;
who->height = height;
who->weight = weight;
return who;
}
void Person_destroy(struct Person *who)
{
assert(who != NULL);
free(who->name);
free(who);
}
void Person_print(struct Person *who)
{
printf("Name: %s\n", who->name);
printf("\tAge: %d\n", who->age);
printf("\tHeight: %d\n", who->height);
printf("\tWeight: %d\n", who->weight);
} }
int main(int argc, char *argv[]) int main(int argc, char *argv[])
{ {
// make two people structures // make two people structures
struct Person *joe = Person_create( struct Person joe = {"Joe Alex", 32, 64, 140};
"Joe Alex", 32, 64, 140); struct Person frank = {"Frank Blank", 20, 72, 180};
struct Person *frank = Person_create(
"Frank Blank", 20, 72, 180);
// print them out and where they are in memory // print them out and where they are in memory
printf("Joe is at memory location %p:\n", joe); printf("Joe is at memory location %p:\n", &joe);
Person_print(joe); Person_print(joe);
printf("Frank is at memory location %p:\n", frank); printf("Frank is at memory location %p:\n", &frank);
Person_print(frank); Person_print(frank);
// make everyone age 20 years and print them again // make everyone age 20 years and print them again
joe->age += 20; joe.age += 20;
joe->height -= 2; joe.height -= 2;
joe->weight += 40; joe.weight += 40;
Person_print(joe); Person_print(joe);
frank->age += 20; frank.age += 20;
frank->weight += 20; frank.weight += 20;
Person_print(frank); Person_print(frank);
// destroy them both so we clean up
Person_destroy(joe);
Person_destroy(frank);
return 0; return 0;
} }