We are executive members who pays $100/year. We also get cash back for every purchase and we pretty much get the membership fee back every year. We are a family of four and we buy most of our home supplies from Costco plus other stuffs. We love Costco but you have to know what you are buying.
Undefined is a term used when a mathematical result has no meaning. More precisely, undefined values occur when an expression is evaluated for input values outside of its domain. ( 1 if no complex numbers) ( 2 if no complex numbers) ( units in radians, no complex infinity)
In the first case (calling the subobject's class method straight through the pointer to the class object), the fact of the pointer being equal to null also corresponds to undefined behavior, and the check is not added here.