学生管理系统C语言代码用到文件学生表课程表成绩表

以下是一个使用文件存储学生表、课程表和成绩表的学生管理系统的代码示例：

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

#define MAX_STUDENTS 100
#define MAX_NAME_LENGTH 50
#define MAX_COURSES 10

struct Student {
    char name[MAX_NAME_LENGTH];
    int age;
    int courseCount;
    char courses[MAX_COURSES][MAX_NAME_LENGTH];
    float scores[MAX_COURSES];
};

struct Student students[MAX_STUDENTS];
int studentCount = 0;

void addStudent() {
    if (studentCount >= MAX_STUDENTS) {
        printf("学生数量已达上限！\n");
        return;
    }

    struct Student newStudent;

    printf("请输入学生姓名：");
    scanf("%s", newStudent.name);

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

    printf("请输入学生选修课程数量：");
    scanf("%d", &newStudent.courseCount);

    for (int i = 0; i < newStudent.courseCount; i++) {
        printf("请输入第%d门课程名称：", i+1);
        scanf("%s", newStudent.courses[i]);

        printf("请输入第%d门课程成绩：", i+1);
        scanf("%f", &newStudent.scores[i]);
    }

    students[studentCount] = newStudent;
    studentCount++;

    printf("添加成功！\n");
}

void printStudents() {
    if (studentCount == 0) {
        printf("没有学生记录！\n");
        return;
    }

    for (int i = 0; i < studentCount; i++) {
        printf("姓名：%s\t年龄：%d\n", students[i].name, students[i].age);

        printf("选修课程和成绩：\n");
        for (int j = 0; j < students[i].courseCount; j++) {
            printf("%s\t%.2f\n", students[i].courses[j], students[i].scores[j]);
        }
    }
}

void saveData() {
    FILE *fp = fopen("students.txt", "w");
    if (fp == NULL) {
        printf("无法打开文件！\n");
        return;
    }

    fprintf(fp, "%d\n", studentCount);
    for (int i = 0; i < studentCount; i++) {
        fprintf(fp, "%s %d %d\n", students[i].name, students[i].age, students[i].courseCount);

        for (int j = 0; j < students[i].courseCount; j++) {
            fprintf(fp, "%s %f\n", students[i].courses[j], students[i].scores[j]);
        }
    }

    fclose(fp);

    printf("数据保存成功！\n");
}

void loadData() {
    FILE *fp = fopen("students.txt", "r");
    if (fp == NULL) {
        printf("无法打开文件！\n");
        return;
    }

    fscanf(fp, "%d", &studentCount);
    for (int i = 0; i < studentCount; i++) {
        fscanf(fp, "%s %d %d", students[i].name, &students[i].age, &students[i].courseCount);

        for (int j = 0; j < students[i].courseCount; j++) {
            fscanf(fp, "%s %f", students[i].courses[j], &students[i].scores[j]);
        }
    }

    fclose(fp);

    printf("数据加载成功！\n");
}

int main() {
    int choice;

    loadData();  // 加载数据

    while (1) {
        printf("\n学生管理系统\n");
        printf("1. 添加学生\n");
        printf("2. 查看学生\n");
        printf("3. 保存数据\n");
        printf("4. 退出\n");
        printf("请选择操作：");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                addStudent();
                break;
            case 2:
                printStudents();
                break;
            case 3:
                saveData();
                break;
            case 4:
                printf("退出程序。\n");
                exit(0);
            default:
                printf("无效的选择！\n");
        }
    }

    return 0;
}

在这个示例中，学生的信息（包括姓名、年龄、选修课程和成绩）被存储在一个结构体数组中，并使用文件进行持久化存储。通过 `saveData()` 函数将数据保存到名为 "students.txt" 的文件中，通过 `loadData()` 函数从文件中加载数据。当程序启动时，会自动加载之前保存的数据。可以根据需要修改文件名和文件格式。