Complete listing of Variables03.cpp, Listing 3
/*File: Variables03.cpp This C++ program illustrates instance variables. This program instantiates two objects of type Variables03 in dynamic memory and stores pointers to the two objects in pointer variables named ptrToObj01 and ptrToObj02. The class named Variables03 has a public instance variable named instanceVariable. The program uses the two pointer variables to store values of 3 and 10 in the instance variable belonging to each of the two objects respectively. Then the program invokes an instance function named displayInstanceVariable on each of the two objects to display the contents of the instance variable encapsulated in each of the two objects. The program displays the following output on the screen: In displayInstanceVariable function 3 In displayInstanceVariable function 10 ************************************************/ #include <iostream> using namespace std; class Variables03{ public: //The following is an instance variable. int instanceVariable; static void classMain(){ //Instantiate two objects in dynamic memory // and save their references in two pointer // variables. Variables03* ptrToObj01 = new Variables03(); Variables03* ptrToObj02 = new Variables03(); //Store different numeric values in the // instance variables belonging to each of // the two objects. ptrToObj01 -> instanceVariable = 3; ptrToObj02 -> instanceVariable = 10; //Invoke the same instance function on each // of the two objects to display the values // contained in the instance variable in // each of the two objects. ptrToObj01 -> displayInstanceVariable(); ptrToObj02 -> displayInstanceVariable(); }//End classMain function //-------------------------------------------// //An instance function of the Variables03 class void displayInstanceVariable(){ cout << "In displayInstanceVariable function\n"; cout << instanceVariable << endl; }//end displayInstanceVariable function };//End Variables03 class //---------------------------------------------// int main(){ Variables03::classMain(); return 0; }//end main Listing 3 |