C Tutorial/ctype.h/isalpha
isalpha
Item Value Header file ctype.h Declaration int isalpha(int ch); Return returns nonzero if ch is a letter or zero if not.
#include <ctype.h>
#include <stdio.h>
int main(void)
{
char ch;
for(;;) {
ch = getchar();
if(ch == ".") {
break;
}
if(isalpha(ch)) {
printf("%c is a letter\n", ch);
}
}
return 0;
}