完成习题16

ex16/ex16.c

@@ -43,7 +43,7 @@ struct Person *Person_create(char *name, int age, int height, int weight)
 void Person_destroy(struct Person *who)
 {
     // 判断结构体是否为空
-    assert(who != NULL);
+    // assert(who != NULL);
 
     // 先释放name所占用的空间，再销毁结构体
     free(who -> name);
@@ -84,11 +84,14 @@ int main(int argc, char *argv[])
 
     frank -> age += 20;
     frank -> weight += 20;
+    Person_destroy(frank);
     Person_print(frank);
+    // Person_print(NULL);
 
     // destroy them both so we clean up
     Person_destroy(joe);
     Person_destroy(frank);
+    // Person_destroy(NULL);
 
     return 0;
 }

ex16/ex16_struct.c

@@ -0,0 +1,70 @@
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct Person 
+{
+    char name[20];
+    int age;
+    int height;
+    int weight;
+};
+
+struct Person Person_create(char name[], int name_length, int age, int height, int weight)
+{
+    struct Person who;
+
+    for (int i = 0; i < name_length; ++i)
+    {
+        who.name[i] = name[i]; 
+    }
+
+    who.name[name_length - 1] = '\0';
+    who.age = age;
+    who.height = height;
+    who.weight = weight;
+
+    return 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[])
+{
+    char name1[20] = "Joe Alex\0";
+    char name2[20] = "Frank Blank\0";
+    // make two people structures
+    struct Person joe = Person_create(name1, 20, 32, 64, 140);
+
+    struct Person frank = Person_create(name2, 20, 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;
+}

ex16/vedio

@@ -0,0 +1 @@
+http://ewm.ptpress.com.cn:8085/preview?qrCode=qr2018001491