isalnum - Test for letter or digit

Definition	#include <ctype.h> int isalnum(int c); isalnum checks whether the character c from the EBCDIC character set is alphanumeric, i.e. a letter (A-Z, a-z) or a digit (0-9).
Return val.	!= 0 0	c is alphanumeric. c is not alphanumeric.
Note	isalnum is implemented both as a macro and as a function (see section “Functions and macros”).
Example	#include <ctype.h> #include <stdio.h> int main(void) { int c; while((c = getchar()) != EOF)     printf("%s : %c\n", ((isalnum(c)) ? "Alphanumeric" : "Other"), c); return 0; }
See also	isalpha, isascii, iscntrl, isdigit, isgraph, islower, ispunct, isprint, isspace, isupper, isxdigit, isebcdic, iswalnum