Question

Assuming the following class declaration:

class   Course {

       private:

              string grade_;

              int       units_;

        public:

             Course ( );

             Course ( string grade, int units);

              ~Course ( );

              string get_grade ( ) const ;

              int       get_units ( ) const;

};

NOTE:

• Class definitions are not provided but you may assume they're properly defined.
• Variable names used in your answers must follow our stated naming convention especially for pointer names.

Write a fragment of code (do not write a program) to:

1. Declare a pointer to a Course object and properly initialize it.

2. This is a separate statement from the declaration statement above: Dynamically create/instantiate a Course object ( with parameters: grade == "A-" and units==5) and assign it to the pointer above.

3. Output the Course's grade and units to the console using pointer syntax.

4. Dynamically allocate an array of 128 Courses objects. You must declare another pointer.

Non-coding question: Which constructor will be used to create/instantiate the elements of the Course array above?

5. Properly de-allocate the array of 128 Course objects.

Answer 1

1. Declare a pointer to a Course object and properly initialize it.
Course *course = NULL; // declare a pointer of Course object which is initialized to NULL since it is not allocated any memory

2. Dynamically create/instantiate a Course object ( with parameters: grade == "A-" and units==5) and assign it to the pointer above.

course = new Course("A-",5); // create a new Course object and assign it to course

3. Output the Course's grade and units to the console using pointer syntax.

cout<<"Grade : "<<course-> get_grade()<<"\n";

cout<<"Units : "<<course-> get_units()<<"\n";

// cout is used for displaying and since course is a pointer we use arrow notation to refer to its member functions

4. Dynamically allocate an array of 128 Courses objects.

Course *coursePtr = new Course[128]; // create an array of 128 Course objects

Default constructor is used to create/instantiate the elements of Course array created dynamically as no values are provided for the Course objects hence, it will be initialized with default values and hence default constructor is called.

5. De-allocate the array of 128 Course objects.

delete [] coursePtr; // release the memory allocated to the coursePtr array