isdigit example

#include <iostream.h>
#include <ctype.h> // for isdigit
main()
{
        char stg[5] = "abcd";
        char stgnum[5] = "3543";
        unsigned int id;
        id = isdigit('0');
        cout << id << '\n';
        id = isdigit('4');
        cout << id << '\n';
        id = isdigit ('A');
        cout << id << '\n';
        id = isdigit ('B');
        cout << id << '\n';
        id = isdigit (stg[0]) ;
        cout << stg[0] << "***"<< id << '\n';
        id = isdigit (stgnum[0]) ;
        cout << stgnum[0] << "***"<< id << '\n';
        id = isdigit (stg[3]) ;
        cout << stg[3] << "***"<< id << '\n';
        id = isdigit (stgnum[3]) ;
        cout << stgnum[3] << "***"<< id << '\n';

return 0;
}
/*
4
4
0
0
a***0
3***4
d***0
3***4
*/