Thread: Checking user input [int/char] (Help)

Originally Posted by Daniell Wang

This's not use lib , like this:

Good, but note that while your check for digit is fine, your check for alphabetic characters make an assumption about their values that is not guaranteed to be true.

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And use the character classification functions in ctype.h

Originally Posted by Daniell Wang

This's not use lib , like this:

Code:

#include<stdio.h>
int main(int argc, char *argv[])
{
    int i;
    printf("Enter something: ");
    i=getchar();
    if(i >= '0' && i <= '9')
        puts("You have entered a number");
    else if((i >='a' && i <= 'z') || (i >='A' && i <= 'Z')) // 
        puts("You have entered an alphabet");
    else
        puts("Invalid input");
}

Doesn't look like he's expecting any command line arguments so it might be better to simply

Code:

 int main(void){...}

As well main always returns an int.