c - scanf()读取自己的输入和后面scanf()的输入

Question

这个错误让我失去了理智，我无法理解它有什么问题。我已经进行了一些调试以使其工作，但它并没有以正确的方式进行。由于某种原因，第一个 scanf() 读取两个输入，它自己的输入和后面的 scanf() 的输入。顺便说一句，我正在使用 %[^\n]s，因为这样它应该读取带有空格的字符串。我怎样才能解决所有问题？

代码:

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

#define MAX_LEN_CODE 6
#define MAX_LEN_STRING 20

typedef struct{
    char course_code[MAX_LEN_CODE];
    char name[MAX_LEN_STRING];
    char trainer[MAX_LEN_STRING];
    int partecipants_max;
    int partecipants_num;
}t_course;

void main(){
    t_course new_course;

    system("clear");
    printf("Insert the code\n");
    printf("> ");
    scanf("%s", new_course.course_code);
    printf("Insert the name of the course\n");
    printf("> ");
    scanf(" %[^\n]s", new_course.name);
    printf("Insert the trainer\n");
    printf("> ");
    scanf("%s", new_course.trainer);
    do{
        printf("Insert the maximum number of partecipants (10-100)\n");
        printf("> ");
        scanf("%d", &new_course.partecipants_max);

        if(new_course.partecipants_max < 10 || 
        new_course.partecipants_max > 100)
            printf("ERROR: The number must be between 10 and 100!\n\n");

    }while(new_course.partecipants_max < 10 || 
        new_course.partecipants_max > 100);

    new_course.partecipants_num = 0;

    printf("\nCODE: %s\nNAME: %s\nTRAINER: %s\nPARTECIPANTS: %d\n", 
        new_course.course_code, new_course.name, 
        new_course.trainer, new_course.partecipants_max);
}

输出:

Insert the code
> aa3040
Insert the name of the course
> fitness and sport
Insert the trainer
> mario
Insert the maximum number of partecipants (10-100)
> 55

CODE: aa3040fitness and sport  // I CAN'T FIGURE OUT THIS STEP
NAME: fitness and sport
TRAINER: mario
PARTECIPANTS: 55

Answer 1

您正在覆盖终止空字符的空间:

你有:

#define MAX_LEN_CODE 6

在你的struct t_course中:

char course_code[MAX_LEN_CODE];

所以 course_code 可以存储 5 个字符 + 1 个用于终止空字符，即 '\0' 来标记字符串的结尾，但是你正在覆盖通过提供 6 个字符来终止空字符:

aa3040

尝试提供 +1 长度:

//changing MAX_LEN_CODE value:
#define MAX_LEN_CODE 7

//or instead of changing MAX_LEN_CODE
//change the size of course_code in your struct:
char course_code[MAX_LEN_CODE + 1];

或者通过提供宽度说明符使scanf()只接受5个字符以避免覆盖末尾的终止空字符:

scanf("%5s", new_course.course_code);

//NOTE: You still need to consume the characters left in stdin
int consume; 
while((consume = getchar()) != '\n' && consume != EOF);