Checking if input is an integer in C

Question

I'm trying to check if a number is an integer (num).

In the main() -

int num, input;
    printf("Please enter an integer greater than 1:\n");
        input = scanf("%d",&num);
        if ( input != 1 ){
            printf("Invalid input!\n");
            return 1;
        }

but when the input is not an integer (33.3 for example), the value of "input" is still 1.

printf("%d ", input);

gives me back 1.

The rest of the program works. Just got stuck on this minor thing.

I don't seem you have done your searches on google before posting this on stackoverflow...Please do some background before asking — Pushan Gupta, May 30 '17 at 12:58

score 1 · Accepted Answer · answered May 30 '17 at 12:54

1

You are going to need to read the input into a char[], (so, no scanf() necessary, you can just do gets() or something similar,) and then check the value yourself, digit by digit, using isdigit().

answered May 30 '17 at 12:54

Mike Nakis

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Checking if input is an integer in C

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