struct Teacher { char *name; int age; }; void test02() { struct Teacher teacher1; teacher1.name = malloc(sizeof(char)* 64); memset(teacher1.name, 0, 64); strcpy(teacher1.name, "aaa"); teacher1.age = 20; struct Teacher teacher2; teacher2.name = malloc(sizeof(char)* 128); memset(teacher2.name, 0, 128); strcpy(teacher2.name, "bbbbbbbbbbbbb"); teacher2.age = 30; printf("Name:%s Age:%d\n", teacher1.name,teacher1.age); printf("Name:%s Age:%d\n", teacher2.name, teacher2.age); printf("teacher1 size: %d\n",sizeof(teacher1)); printf("teacher2 size: %d\n", sizeof(teacher2)); //赋值操作 //不使用默认的结构体赋值行为 //teacher1 = teacher2; //如果结构体内部有指针指向堆内存，那么就不能使用编译器默认的赋值行为，应该手动控制赋值过程。 //---------------------------------------------- if (teacher1.name != NULL) { free(teacher1.name); teacher1.name = NULL; } teacher1.name = malloc(strlen(teacher2.name) + 1); strcpy(teacher1.name, teacher2.name); teacher1.age = teacher2.age; //---------------------------------------------- printf("---------------\n"); printf("Name:%s Age:%d\n", teacher1.name, teacher1.age); printf("Name:%s Age:%d\n", teacher2.name, teacher2.age); //释放堆内存 if (teacher1.name != NULL) { free(teacher1.name); teacher1.name = NULL; } if (teacher2.name != NULL) { free(teacher2.name); teacher2.name = NULL; } } 详细注释这段代码，每一句的作用意义都解释一下

下面是对代码中每一句的详细注释解释：

struct Teacher
{
    char *name;
    int age;
};

定义了一个结构体类型Teacher，包含name和age两个成员。

void test02()
{
    struct Teacher teacher1;
    teacher1.name = malloc(sizeof(char) * 64);
    memset(teacher1.name, 0, 64);
    strcpy(teacher1.name, "aaa");
    teacher1.age = 20;
    
    // 创建teacher1结构体变量，为name分配64字节的内存，并将其初始化为空字符串。
    // 然后将名字赋值为"aaa"，年龄赋值为20。

    struct Teacher teacher2;
    teacher2.name = malloc(sizeof(char) * 128);
    memset(teacher2.name, 0, 128);
    strcpy(teacher2.name, "bbbbbbbbbbbbb");
    teacher2.age = 30;

    // 创建teacher2结构体变量，为name分配128字节的内存，并将其初始化为空字符串。
    // 然后将名字赋值为"bbbbbbbbbbbbb"，年龄赋值为30。

    printf("Name:%s Age:%d\n", teacher1.name, teacher1.age);
    printf("Name:%s Age:%d\n", teacher2.name, teacher2.age);

    // 打印输出teacher1和teacher2的名字和年龄。

    printf("teacher1 size: %d\n", sizeof(teacher1));
    printf("teacher2 size: %d\n", sizeof(teacher2));

    // 打印输出teacher1和teacher2占用的内存大小。

    if (teacher1.name != NULL)
    {
        free(teacher1.name);
        teacher1.name = NULL;
    }

    teacher1.name = malloc(strlen(teacher2.name) + 1);
    strcpy(teacher1.name, teacher2.name);
    teacher1.age = teacher2.age;

    // 释放teacher1之前分配的内存，然后为name重新分配内存，并将其赋值为teacher2的name。
    // 最后将teacher1的年龄赋值为teacher2的年龄。

    printf("---------------\n");
    printf("Name:%s Age:%d\n", teacher1.name, teacher1.age);
    printf("Name:%s Age:%d\n", teacher2.name, teacher2.age);

    // 打印输出修改后的teacher1和未修改的teacher2的名字和年龄。

    if (teacher1.name != NULL)
    {
        free(teacher1.name);
        teacher1.name = NULL;
    }

    if (teacher2.name != NULL)
    {
        free(teacher2.name);
        teacher2.name = NULL;
    }

    // 释放teacher1和teacher2分配的内存。
}

希望以上解释对你有帮助！如果还有其他问题，请随时提问。