back to version that uses malloc/free and pointers

ex16.c

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