1 / * *********************************************** ************************** 2 *********************** ************************************************** ** 3 program case *** 4 a child, because of the limited conditions, teachers often are given a question on the blackboard for students to copy the first question, and then write *** 5 answers, but now teachers are teachers send printed papers, everyone just write the answer on the line, quite *** 6 to alleviate the problems of the students copy duplication of work *** 7 core idea *** 8 Ba move to change the behavior of the parent class, subclass removal repeat Code *** 9 *** 10 key points *** 11 using the parent class virtual function in the function, the answer to extend in different subclasses, i.e. three object-oriented programming Laid *** 12 is polymorphism (encapsulation, inheritance of resistance and polymorphic) *** 13 ******************************************* ******************************** 14 ***************** ************************************************** ******* * / 15 #include <the iostream> 16 #include < String > . 17 the using namespace STD; 18 is . 19 class TestPaper 20 is { 21 is public : 22 is void to Question1 () 23 is { 24 COUT << " first question: 2 + 3 is equal to A: B 3: C. 4:. 5 D:. 6 " << endl; 25 COUT << " answer: " answer1 << () << endl; 26 is }; 27 Virtual String answer1 () 28 { 29 return "" ; 30 }; 31 is }; 32 33 is class student1:public TestPaper 34 { 35 public : 36 String answer1 () 37 [ { 38 is return " first student select A " ; 39 } 40 }; 41 is 42 is class STUDENT2: public TestPaper 43 is { 44 is public : 45 String answer1 () 46 is { 47 return " of two students choose B " ; 48 } 49 }; 50 51 is int main () 52 is { 53 Student1 m_student1; 54 m_student1.Question1(); 55 Student2 m_student2; 56 m_student2.Question1(); 57 58 getchar(); 59 return 0; 60 }
Output:
