Question

Here is my code!(sorry for my poor english)

#include<stdio.h>

int convert(char ch);

int main(void)
{
     char ch=0;

     while(ch != 'q')
     {
         ch=getchar();
         ch=convert(ch);
         if(ch == -1)
            printf("wrong input");
         else 
            putchar(ch);
            putchar('\n');
     }

     return 0;
}

int convert(char ch)
{
    if(ch>='A' && ch<='Z')
        ch+=32;
    else if(ch>='a' && ch<='z')
        ch-=32;
    else
        return -1;
}

And this code is for changing A to a, z to Z
convert small to capital lettor, or reverse.

but when done, i found something wierd cuz whenever i put a char to the program,

it always return both the result that i expected and another “wrong input”.
and i didnt put anything to my standard input except a charactor and a Enter.

So, here is my question.

The function getchar() or some other like fgetc, fgets recieve a ‘enter’ as a charactor?

Answer 1

The function getchar() or some other
like fgetc, fgets recieve a ‘enter’ as
a charactor?

Yes, ‘Enter’ is character 10. You can see this by adding one extra line:

ch=getchar();
printf("Received: %d\n", ch);
ch=convert(ch);

abc
Received: 97

Received: 98

Received: 99

Received: 10