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		expression patientPtr denotes a struct variable of type PatientRec. Furthermore, the expressions (patientPtr).idNum, (patientPtr).height, and (patientPtr).weight denote the idNum, height, and weight members of *patientPtr. Notice how the accessing expression is built.



		patientPtr



		A pointer variable of type pointer to PatientRec.



		*patientPtr



		A struct variable of type PatientRed.



		(*patientPtr).weight



		The weight member of a struct variable of type PatientRec.



		The expression (patientPtr).weight is a mixture of pointer dereferencing and struct member selection. The parentheses are necessary because the dot operator has higher precedence than the dereference operator (see Appendix B for C++ operator precedence). Without the parentheses, the expression patientPtr.weight would be interpreted wrongly as *(patientPtr.weight).



		When a pointer points to a struct (or a class or a union) variable, enclosing the pointer dereference within parentheses can become tedious. In addition to the dot operator, C++ provides another member selection operator: ->. This arrow operator consists of two consecutive symbols: a hyphen and a greater-than symbol. By definition,



		PointerExpression -> MemberName



		is equivalent to



		(*PointerExpression).MemberName



		Therefore, we can write (*patientPtr).weight as patientPtr->weight. The general guideline for choosing between the two member selection operators (dot and arrow) is the following:



		Use the dot operator if the first operand denotes a struct, class, or union variable; use the arrow operator if the first operand denotes a pointer to a struct, class, or union variable.



		If we want to increment and print the TimeType class object pointed to by timePtr, we could use either the statements



		(timePtr).Increment(); (timePtr).Write();



		or the statements



		timePtr->Increment(); timePtr->Write();



		And if we had declared an array of pointers

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