411 REFERENCE · Wikibooks
C++ Programming/Code/Standard C Library/Functions/isalnum
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
isalnum
#include <cctype>
int isalnum( int ch );
The function isalnum() returns non-zero if its argument is a numeric digit or a letter of the alphabet. Otherwise, zero is returned.
char c;
scanf( "%c", &c );
if( isalnum(c) )
printf( "You entered the alphanumeric character %c\n", c );
Related topics isalpha - iscntrl - isdigit - isgraph - isprint - ispunct - isspace - isxdigit