so my code looks like this:

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <math.h>
#include <string.h>

int main(int argc, char *argv[]) {

char password [20];

printf( "Input a password with an upper case, a lower case, and a dollar sign:");
scanf( "%s", password);


printf("%s is my password", password);

printf( "%s is cool", password);

return 0;


and all of them work fine except the type file. I get a warning that says this:
Untitled.c:15:14: warning: incompatible pointer to integer conversion passing 'char [20]' to parameter of type 'int' [-Wint-conversion]
/usr/include/ctype.h:237:13: note: passing argument to parameter '_c' here
isdigit(int _c)
1 warning generated.