study pointer and array

The variable 'ar' is being used without being initialized

int _tmain(int argc, _TCHAR* argv[])
{
char* ar;

*ar = 'a';
printf ("%c\n", *ar);

return 0;
}

fix 1,

int _tmain(int argc, _TCHAR* argv[])
{
char* ar;
char p;

ar = &p;

*ar = 'a';
printf ("%c\n", *ar);

return 0;
}

Output:
a

fix 2,

int _tmain(int argc, _TCHAR* argv[])
{
char* ar;
ar = new char [8];

*ar = 'a';
printf ("%c\n", *ar);

return 0;
}

Output:
a