tYSR20

186Part III: Introduction to Classes}// wait until user is ready before terminating program// to allow the user to see the program resultssystem(“PAUSE”);return 0;The program declares a variable s of type Student. It then goes on to declarea pointer variable pS of type pointer to a Student object, also writtenas Student*. The program initializes the value of one of the data members ins. It then precedes to assign the address of s to the variable pS. Finally, itrefers to the same Student object, first using the object’s name, s, and thenusing the pointer to the object, pS. I explain the strange notation pS->gpa; inthe next section of this chapter.Dereferencing an object pointerBy analogy of pointers to simple variables, you might think that the followingrefers to the GPA of student s:int main(int argc, char* pArgs[]){// the following is incorrectStudent s;Student* pS = &s; // create a pointer to s// access the gpa member of the object pointed at by pS// (this doesn’t work)*pS.gpa = 3.5;}return 0;As the comments indicate, this doesn’t work. The problem is that the dotoperator (.) is evaluated before the pointer (*).Note: The * operator is often referred to as the splat operator — not a popularterm with insects.C++ programmers use parentheses to override the order in which operationsare performed. For example, the parentheses force addition to be performedbefore multiplication in the following expression:int i = 2 * (1 + 3); // addition performed// before multiplicationParentheses have the same effect when applied to pointer variables:int main(int argc, char* pArgs[]){