Item Value
Header filectype.h
Declarationint isalnum(int ch);
Returnreturns nonzero if its argument is either a letter of the alphabet or a digit. returns zero if the character is not alphanumeric.
#include
#include
int main(void)
{
char ch;
printf(". to exit:");
for(;;) {
ch = getc(stdin);
if(ch == '.')
break;
if(isalnum(ch))
printf("%c is alphanumeric\n", ch);
}
return 0;
}
2 is alphanumeric
1 is alphanumeric
1
1 is alphanumeric
2
2 is alphanumeric
12
1 is alphanumeric
2 is alphanumeric
1
1 is alphanumeric
1
1 is alphanumeric
1
1 is alphanumeric
!
~
.