User input validation to check a number.

//User input validation to check a number.

#include<stdio.h>
int main()
{
char chr;
printf("Enter a number: ");
scanf("%c",&chr);

if(isdigit(chr))
printf("It is a number.");
else
printf("It is not a number.");
 return 0;
}

//Output 1
Enter a number: 5
It is a number.

//Output 2
Enter a number: a
It is not a number.