c - 每当我选择 2 时，如何设置 if 语句选项以使其正常工作？

Question

在这段代码中，if 语句给我带来了问题。每当我尝试选择选项 2 时，它都没有给我选择 2的消息？如何使这个 if 语句工作？

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

void hello(){
    int option;
    static const char * listing[] = {"Name", "Date of birth","ID card number"};
    FILE * fr3 = fopen("file.txt","r");

    if (fr3 == NULL) {
        perror("Unable to read text file.");
        exit(0);
    }
    for (option = 1; option <= sizeof(listing)/sizeof(char *); ++option)
       printf("%d. Your %s\n", option, listing[option-1]);  

    fputs("Select your choice to update: ", stdout);   
    if (scanf("%d", &option) == 1) {
        puts("selected 1");
        fclose(fr3);
        exit(0);
    }
    if (scanf("%d", &option) == 2) {
        puts("selected 2");
        fclose(fr3);
        exit(0);
    }
      fclose(fr3);
}
int main(){ hello(); }

标签： cif-statement

Answer 1

我已经转移到了scanf("%d", &option)if 语句之外。因此，请检查以下代码：

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

void hello(){
    int option;
    static const char * listing[] = {"Name", "Date of birth","ID card number"};
    FILE * fr3 = fopen("file.txt","r");

    if (fr3 == NULL) {
        perror("Unable to read text file.");
        exit(0);
    }
    
    for (option = 1; option <= sizeof(listing)/sizeof(char *); ++option)
       printf("%d. Your %s\n", option, listing[option-1]);  
    
    fputs("Select your choice to update: ", stdout);   
    scanf("%d", &option);
    if (option == 1) {
        puts("selected 1");
        fclose(fr3);
        exit(0);
    }
    if (option == 2) {
        puts("selected 2");
        fclose(fr3);
        exit(0);
    }
      fclose(fr3);
}
int main(){ hello(); }