在C和C++中通过指针访问结构

#include <stdio.h>
#include <stdlib.h>

struct Student {
    char name[50];
    int age;
};

void printStudent(struct Student *ptr) {
    printf("Name: %s, Age: %d\n", ptr->name, ptr->age);
}

int main() {
    struct Student student = {"Alice", 20};
    struct Student *ptr = &student;

    printStudent(ptr);

    // 修改结构体成员
    ptr->age = 21;
    printf("Updated Age: %d\n", ptr->age);

    return 0;
}

struct Student *ptr = NULL;
// 确保在使用ptr之前进行初始化
ptr = (struct Student *)malloc(sizeof(struct Student));
if (ptr == NULL) {
    fprintf(stderr, "Memory allocation failed\n");
    exit(1);
}

struct Student *ptr = (struct Student *)malloc(sizeof(struct Student));
// 使用ptr
// ...
free(ptr); // 释放内存

struct Student *studentPtr = (struct Student *)malloc(sizeof(struct Student));
// 错误示例
struct Teacher *teacherPtr = studentPtr; // 类型不匹配