报错scanf("%s", stu.num);无法运行
时间: 2023-11-27 14:47:08 浏览: 36
以下是关于报错scanf("%s", stu.num);无法运行的解释和演示:
1. 报错原因是因为scanf函数中的%s格式化字符串对应的是一个字符数组,而stu.num可能是一个字符指针,导致无法正确运行。正确的写法应该是使用scanf_s函数。
```c
char a[10];
scanf_s("%s", a, 9);
printf("键盘上输入的字符串是:%s\n", a);
```
2. sizeof操作符可以用来获取变量、常量或数据类型所占的字节数。它有几种形式,包括sizeof( 变量\常量 )、sizeof( 数据类型 )等。
```c
sizeof(10);
char c = 'a';
sizeof(c);
sizeof(float);
```
相关问题
#include<stdio.h> struct student { *学生信息结构定义* int num; 冰学号* char name[10]; 冰姓名* intcomputer,english,math;1*三门课程成繢*/ double average; *个人平均成绩*/ }; int main() int i, n; struct student stu,max; 冰定义结构变量* printf ("Input n: "); scanf ("%d", &n); printf ("Input the student's number, name and course scores\n"); for (i = 1; i <= n; i++){ printf ("No.%d: ", i); scanf %d".&stu.num,stu.name,&stu.math,&stu.english,&stu.computer); stu.average = (stu.math + stu.english + stu.computer) / 3.0; if (i == 1){ max = stu; 冰结构变量赋值*/ Felseif(max.average<stu.average){ max = stu; ["%d%5%d%d 冰结构变量赋值*/ Felseif(max.average<stu.average){ max = stu; ["%d%5%d%d printf("num:%d, max.average); return 0; name:%5, average:%.2Ifn", max.num, max.name, ) return 0; }向这个代码里面添加查询和修改功能
要添加查询和修改功能,需要在主函数中添加相应的代码。下面是修改后的代码:
```c
#include <stdio.h>
#include <string.h>
struct student {
int num; // 学号
char name[10]; // 姓名
int computer; // 计算机成绩
int english; // 英语成绩
int math; // 数学成绩
double average; // 平均成绩
};
int main() {
int i, n, choice, num;
struct student stu, max = {0};
printf("Input n: ");
scanf("%d", &n);
printf("Input the student's number, name and course scores\n");
for (i = 1; i <= n; i++) {
printf("No.%d: ", i);
scanf("%d%s%d%d%d", &stu.num, stu.name, &stu.math, &stu.english, &stu.computer);
stu.average = (stu.math + stu.english + stu.computer) / 3.0;
if (i == 1) {
max = stu;
} else if (max.average < stu.average) {
max = stu;
}
}
printf("num:%d, name:%s, average:%.2f\n", max.num, max.name, max.average);
// 添加查询和修改功能
printf("Enter 1 to query a student's information, 2 to modify a student's information: ");
scanf("%d", &choice);
if (choice == 1) {
printf("Enter the student's number: ");
scanf("%d", &num);
for (i = 1; i <= n; i++) {
printf("No.%d: ", i);
scanf("%d%s%d%d%d", &stu.num, stu.name, &stu.math, &stu.english, &stu.computer);
stu.average = (stu.math + stu.english + stu.computer) / 3.0;
if (stu.num == num) {
printf("num:%d, name:%s, math:%d, english:%d, computer:%d, average:%.2f\n", stu.num, stu.name, stu.math, stu.english, stu.computer, stu.average);
break;
}
}
if (i > n) {
printf("Student not found.\n");
}
} else if (choice == 2) {
printf("Enter the student's number: ");
scanf("%d", &num);
for (i = 1; i <= n; i++) {
printf("No.%d: ", i);
scanf("%d%s%d%d%d", &stu.num, stu.name, &stu.math, &stu.english, &stu.computer);
stu.average = (stu.math + stu.english + stu.computer) / 3.0;
if (stu.num == num) {
printf("Enter the new information:\n");
scanf("%d%s%d%d%d", &stu.num, stu.name, &stu.math, &stu.english, &stu.computer);
stu.average = (stu.math + stu.english + stu.computer) / 3.0;
printf("num:%d, name:%s, math:%d, english:%d, computer:%d, average:%.2f\n", stu.num, stu.name, stu.math, stu.english, stu.computer, stu.average);
break;
}
}
if (i > n) {
printf("Student not found.\n");
}
} else {
printf("Invalid choice.\n");
}
return 0;
}
```
在上面的代码中,我们添加了一个 `choice` 变量,用于选择查询或修改功能。当用户选择查询时,我们需要再次输入要查询的学生的学号,然后遍历学生数组,找到对应学号的学生,输出其信息。当用户选择修改时,我们也需要输入要修改的学生的学号,然后遍历学生数组,找到对应学号的学生,再次输入该学生的信息,更新结构体中的信息。如果找不到对应学号的学生,输出相应的错误信息。
#include "stdio.h" struct student { int num; /*学号*/ char name[30]; /*姓名*/ int math,english,computer; /*3门课成绩*/ int total; }; int main() { struct student stu,max; int i; for(i=0;i<3;i++) { scanf("%d %s %d %d %d",&stu.num,stu.name,&stu.math,&stu.english,&stu.computer); ________________________________; printf("%d %s %d %d %d %d\n",stu.num,stu.name,stu.math,stu.english,stu.computer,stu.total); if(i==0) { max=stu; } else { if(_____________________) { ____________________; } } } printf("%d %s %d %d %d %d",max.num,max.name,max.math,max.english,max.computer,max.total); return 0; }
这段代码中有两处需要填空:
第一处需要计算每个学生的总分,可以在输入数据后添加如下代码:
```c
stu.total = stu.math + stu.english + stu.computer;
```
第二处需要比较每个学生的总分,找出最高分的学生,可以在if语句中添加如下代码:
```c
if(stu.total > max.total)
{
max = stu;
}
```
修改后的完整代码如下:
```c
#include "stdio.h"
struct student {
int num; /*学号*/
char name[30]; /*姓名*/
int math, english, computer; /*3门课成绩*/
int total;
};
int main() {
struct student stu, max;
int i;
for(i = 0; i < 3; i++) {
scanf("%d %s %d %d %d", &stu.num, stu.name, &stu.math, &stu.english, &stu.computer);
stu.total = stu.math + stu.english + stu.computer;
printf("%d %s %d %d %d %d\n", stu.num, stu.name, stu.math, stu.english, stu.computer, stu.total);
if(i == 0) {
max = stu;
}
else {
if(stu.total > max.total) {
max = stu;
}
}
}
printf("%d %s %d %d %d %d", max.num, max.name, max.math, max.english, max.computer, max.total);
return 0;
}
```