Up through lcthw exercise 16

lcthw/ex15.c

@@ -13,8 +13,16 @@ int main(int argc, char *argv[])
 	int count = sizeof(ages) / sizeof(int);
 	int i = 0;
 
+	char **first_name = &names[0];
+	char **last_name = &names[count - 1];
+
+	printf("first_name=%p last_name=%p\n", first_name, last_name);
+	printf("*first_name=%s *last_name=%s\n", *first_name, *last_name);
+
+	printf("---\n");
+
 	// first way using indexing
-	for (i = 0; i < count; i++) {
+	for (i = count - 1; i > -1; i--) {
 		printf("%s has %d years alive.\n", names[i], ages[i]);
 	}
 
@@ -25,14 +33,14 @@ int main(int argc, char *argv[])
 	char **cur_name = names;
 
 	// second way using pointers
-	for (i = 0; i < count; i++) {
+	for (i = count - 1; i > -1; i--) {
 		printf("%s is %d years old.\n", *(cur_name + i), *(cur_age + i));
 	}
 
 	printf("---\n");
 
 	// third way, pointers are just arrays
-	for (i = 0; i < count; i++) {
+	for (i = count - 1; i > -1; i--) {
 		printf("%s is %d years old again.\n", cur_name[i], cur_age[i]);
 	}
 

lcthw/ex16.c

@@ -0,0 +1,71 @@
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct Person {
+	char *name;
+	int age;
+	int height;
+	int weight;
+};
+
+struct Person *Person_create(char *name, int age, int height, int weight)
+{
+	struct Person *who = malloc(sizeof(struct Person));
+	assert(who != NULL);
+
+	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 = Person_create("Joe Alex", 32, 64, 100);
+
+	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);
+	Person_print(joe);
+
+	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->height -= 2;
+	joe->weight += 40;
+	Person_print(joe);
+
+	frank->age += 20;
+	frank->weight += 20;
+	Person_print(frank);
+
+	// destroy them both so we clean up
+	Person_destroy(joe);
+	Person_destroy(frank);
+
+	return 0;
+}