C语言中实现自定义数据类型的输入输出的方法和技巧

#include <stdio.h>

// 定义一个学生结构体
struct Student {
    char name[50];
    int age;
    float score;
};

int main() {
    struct Student stu;

    // 输入学生信息
    printf("请输入学生姓名：");
    scanf("%s", stu.name);

    printf("请输入学生年龄：");
    scanf("%d", &stu.age);

    printf("请输入学生成绩：");
    scanf("%f", &stu.score);

    // 输出学生信息
    printf("学生姓名：%s\n", stu.name);
    printf("学生年龄：%d\n", stu.age);
    printf("学生成绩：%.2f\n", stu.score);

    return 0;
}

#include <stdio.h>

// 定义一个星期枚举类型
enum Weekday {
    MONDAY,
    TUESDAY,
    WEDNESDAY,
    THURSDAY,
    FRIDAY,
    SATURDAY,
    SUNDAY
};

int main() {
    enum Weekday day;

    // 输入星期
    printf("请输入星期（0 - 6）: ");
    int num;
    scanf("%d", &num);

    // 检查输入是否有效
    if (num >= 0 && num <= 6) {
        day = (enum Weekday)num;
    } else {
        printf("输入无效，请重新输入\n");
        return 1;
    }

    // 输出星期
    switch (day) {
        case MONDAY:
            printf("星期一\n");
            break;
        case TUESDAY:
            printf("星期二\n");
            break;
        case WEDNESDAY:
            printf("星期三\n");
            break;
        case THURSDAY:
            printf("星期四\n");
            break;
        case FRIDAY:
            printf("星期五\n");
            break;
        case SATURDAY:
            printf("星期六\n");
            break;
        case SUNDAY:
            printf("星期日\n");
            break;
    }

    return 0;
}

#include <stdio.h>

// 定义一个联合类型
union Data {
    int intValue;
    float floatValue;
    char charValue;
};

int main() {
    union Data data;

    // 输入数据类型和值
    printf("请选择输入的数据类型（1 - int，2 - float，3 - char）: ");
    int choice;
    scanf("%d", &choice);

    switch (choice) {
        case 1:
            printf("请输入一个整数: ");
            scanf("%d", &data.intValue);
            break;
        case 2:
            printf("请输入一个浮点数: ");
            scanf("%f", &data.floatValue);
            break;
        case 3:
            printf("请输入一个字符: ");
            scanf(" %c", &data.charValue);
            break;
        default:
            printf("无效的选择\n");
            return 1;
    }

    // 输出数据
    printf("选择的类型和值: ");
    switch (choice) {
        case 1:
            printf("整数: %d\n", data.intValue);
            break;
        case 2:
            printf("浮点数: %f\n", data.floatValue);
            break;
        case 3:
            printf("字符: %c\n", data.charValue);
            break;
    }

    return 0;
}

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

// 定义链表节点结构体
struct ListNode {
    int data;
    struct ListNode *next;
};

// 创建新节点
struct ListNode* createNode(int data) {
    struct ListNode* newNode = (struct ListNode*)malloc(sizeof(struct ListNode));
    newNode->data = data;
    newNode->next = NULL;
    return newNode;
}

// 打印链表
void printList(struct ListNode* head) {
    struct ListNode* current = head;
    while (current!= NULL) {
        printf("%d ", current->data);
        current = current->next;
    }
    printf("\n");
}

int main() {
    struct ListNode* head = NULL;
    struct ListNode* temp;

    // 输入节点数据并构建链表
    int data;
    printf("请输入节点数据（输入 -1 结束）: ");
    scanf("%d", &data);

    while (data!= -1) {
        temp = createNode(data);

        if (head == NULL) {
            head = temp;
        } else {
            struct ListNode* current = head;
            while (current->next!= NULL) {
                current = current->next;
            }
            current->next = temp;
        }

        scanf("%d", &data);
    }

    // 输出链表
    printf("链表中的数据: ");
    printList(head);

    // 释放链表内存
    struct ListNode* curr = head;
    struct ListNode* next;

    while (curr!= NULL) {
        next = curr->next;
        free(curr);
        curr = next;
    }

    return 0;
}

#include <stdio.h>

// 定义一个学生结构体
struct Student {
    char name[50];
    int age;
    float score;
};

int main() {
    struct Student stu;
    FILE *fp;

    // 输入学生信息
    printf("请输入学生姓名：");
    scanf("%s", stu.name);

    printf("请输入学生年龄：");
    scanf("%d", &stu.age);

    printf("请输入学生成绩：");
    scanf("%f", &stu.score);

    // 打开文件进行写入
    fp = fopen("student.txt", "w");
    if (fp == NULL) {
        printf("无法打开文件\n");
        return 1;
    }

    // 将结构体数据写入文件
    fwrite(&stu, sizeof(struct Student), 1, fp);

    // 关闭文件
    fclose(fp);

    // 打开文件进行读取
    fp = fopen("student.txt", "r");
    if (fp == NULL) {
        printf("无法打开文件\n");
        return 1;
    }

    // 读取结构体数据
    struct Student readStu;
    fread(&readStu, sizeof(struct Student), 1, fp);

    // 输出读取的学生信息
    printf("从文件中读取的学生信息:\n");
    printf("学生姓名：%s\n", readStu.name);
    printf("学生年龄：%d\n", readStu.age);
    printf("学生成绩：%.2f\n", readStu.score);

    // 关闭文件
    fclose(fp);

    return 0;
}