Mega Code Archive
Isalnum
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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 <ctype.h>
#include <stdio.h>
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
!
~
.
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