warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-res

在PAT上写C代码的时候出现 warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
 

原因：使用scanf的时候有一个返回值

#include 

int main() {
    int a;
    scanf("%d", &a);
    printf("%d", a);
    return 0;
}

​

 

a.c: In function ‘main’:
a.c:5:2: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ^~~~~~~~~~~~~~

解决：编写代码的时候给scanf一个返回值即可

#include 

int main() {
    int a;

    if(scanf("%d", &a)){   
        printf("%d", a);
    }else{
        printf("error");
    }
    return 0;
}

​