Null is equivalent to what number:

$2)$ Declare the variable ptr that can contain the address of an int:

$3)$ Declare the variable ptr$2$ that can contain the address of a float

$4)$ Given the following snippet of code

int a$=5$;

printf$("\%$p$",???)$;

what would you replace the $???$ with in order to display the address of the variable a:

$5)$ Given a variable called var, how would you display the address of where the variable var is stored: