Question

I have a signed integer variable
when I do this in main, it is giving me “Error” for integer values as well.

int main(){
    unsigned int a;
    while(cin>>a){
        if(!isdigit(a)){
            cout<<"Error"<<endl;
        }
    }
}

[EDIT]:
Thanks to all the responses, I understood the issue. Now, how do I check if cin is reading integer only and not alphabets or any other character. Is there any function for that in c++. Thanks

Answer 1

The problem is that isdigit() takes a character, not an integer.

It returns true when the character is '0', '1', etc… Which has ascii values of 48, 49, etc…

Try it this way instead:

char a;
while(cin>>a){
    if(!isdigit(a)){