c语言怎么实现修改功能

要实现修改功能，首先需要获取用户输入的数据，并根据用户输入的信息找到对应的数据进行修改。以下是一个简单的示例代码来实现修改功能：

#include <stdio.h>#include <string.h>struct Student {    char name[50];    int age;};int main() {    struct Student students[10];    int numStudents = 0;    int choice, index;        do {        printf("\n1. Add student\n");        printf("2. Modify student\n");        printf("3. Exit\n");        printf("Enter your choice: ");        scanf("%d", &choice);                switch(choice) {            case 1:                printf("\nEnter student name: ");                scanf("%s", students[numStudents].name);                printf("Enter student age: ");                scanf("%d", &students[numStudents].age);                numStudents++;                break;                            case 2:                printf("\nEnter index of student to modify (0-%d): ", numStudents-1);                scanf("%d", &index);                if (index >= 0 && index < numStudents) {                    printf("Enter new name for student: ");                    scanf("%s", students[index].name);                    printf("Enter new age for student: ");                    scanf("%d", &students[index].age);                } else {                    printf("Invalid index\n");                }                break;                            case 3:                break;                            default:                printf("Invalid choice\n");        }    } while (choice != 3);        printf("\nList of students:\n");    for (int i = 0; i < numStudents; i++) {        printf("%d. %s, %d\n", i, students[i].name, students[i].age);    }        return 0;}

这段代码定义了一个学生结构体Student，可以添加学生信息和修改学生信息。用户可以选择添加学生信息、修改学生信息或退出程序。程序会一直运行直到用户选择退出。