C语言：深复制VS浅复制 数组VS指针

计算机是32位的，编译器是dev-cpp。

C源码：

#include <stdio.h>

struct student{
       char *name1;
       char name2[20];
}stu;

int main()
{
    struct student *p;
    p = &stu;
    //strcpy((*p).name1,"first");// 编译正确，运行错误，因为没有分配空间。
    strcpy((*p).name2,"second");  // 深复制：复制数组所有的字符 
    printf("name1 = %s \t name2 = %s\n",(*p).name1,(*p).name2);
    
    p->name1 = "third";   // 浅复制，只复制内存地址 
    printf("name1 = %s \t name2 = %s\n",(*p).name1,(*p).name2);
    //p->name2 = "fourth";  //编译错误： incompatible types in assignment of `const char[7]' to `char[20]' 
    char tp[20]="fifth";  
    //p->name2 = tp;  //编译错误：ISO C++ forbids assignment of arrays 
    // 深复制和浅复制的区别 
    strcpy((*p).name2,tp);
    p->name1 = tp;
    tp[0]='F';//修改tp字符串的值
    printf("name1 = %s \t name2 = %s\n",(*p).name1,(*p).name2); // 浅复制的值发生改变，深复制不会
    
    // 字符串数组和指针的区别
    printf("sizeof(char *name) = %d\nsizeof(char name[20]) = %d\n", sizeof(p->name1), sizeof(p->name2)); // 32位计算机4和20 
    system("PAUSE");
    return 0;
}

运行结果为：

name1 = (null)   name2 = second
name1 = third    name2 = second
name1 = Fifth    name2 = fifth
sizeof(char *name) = 4
sizeof(char name[20]) = 20