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  #include   struct Student {     char name[50];     int age; };  int main() {     struct Student students[10];     int numStudents = 0;     int choice, index;          do {         printf("n1. Add studentn");         printf("2. Modify studentn");         printf("3. Exitn");         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 indexn");                 }                 break;                              case 3:                 break;                              default:                 printf("Invalid choicen");         }     } while (choice != 3);          printf("nList of students:n");     for (int i = 0; i < numStudents; i++) {         printf("%d. %s, %dn", 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。