![Page 8
Pointer To Objects
We can also create the objects using pointers and new
operator as:
item * ptr = new item ;
This statement allocates enough memory for the data members in
the object structure and assigns the address of the memory space
to ptr.
We can also create an array of objects using pointers
Item *ptr = new item[10];
Creates memory space for an array of 10 objects of item.
continue…](https://image.slidesharecdn.com/chap9pointersvirtualfunctionsandpolymorphisms-160311142023/85/pointers-virtual-functions-and-polymorphisms-in-c-in-cpp-8-320.jpg)
pointers, virtual functions and polymorphisms in c++ || in cpp
- 1. Chapter 9 Pointers, Virtual functions & Polymorphism
- 2. Page 2 Contents •Introduction •Pointers •Pointers to objects •this pointers •pointers to derived class •virtual functions •pure virtual function
- 3. Page 3 Early Binding or Compile Time Polymorphism The concept of polymorphism is implemented using overloaded functions and operators. The overloaded memberfunctions are selected forinvoking by matching arguments, both type and numbers. This information is known to the compilerat the compile time and, therefore, compileris able to select the appropriate function fora particular call at the compile time itself. This is called early binding orstatic binding or static linking.
- 4. Page 4 Late Binding or Run Time Polymorphism class A { int x; public: void show( ) {……} }; class B : public A { int y; public: void show( ) {……} }; Since the prototype of show( ) is the same in both the places, the function is not overloaded and therefore static binding does not apply. The class resolution operatoris used to specify the class while invoking the functions with the derived class. Appropriate member function is selected while the program is running.
- 5. Page 5 Late Binding or Run Time Polymorphism The appropriate version of function will be invoked at runtime. Since the function is linked with a particularclass much laterafterthe compilation, this process is termed as late binding. This also known as dynamic binding, since the selection of appropriate function is done Polymorphism Compile time Run time Function Overloading Operator Overloading Virtual Functions Achieving Polymorphism
- 6. Page 6 Pointer To Objects item * it_ptr; whereitemis aclass andit_ptris apointerof typeitem. Object pointers are useful in creats objects at run time. An object pointercan be used to access the public members of an object.
- 7. Page 7 Pointer To Objects class item { int code; float price; public: void getdata( int a, float b ) { code =a; price = b;} void show( void ) { cout << “Code :” << code<<endl; << “Price :” << price << endl; } }; item x; item *ptr = &x; We can referto the memberfunctions of item in two ways: Using dot operatorand object. x.getdata(100,75.50); x.show( ); Using arrow operatorand object pointer. ptr-> getdata(100, 75.50); ptr-> show( ); Since *ptris an alias of x (*ptr).show( ); continue…
- 8. Page 8 Pointer To Objects We can also create the objects using pointers and new operator as: item * ptr = new item ; This statement allocates enough memory for the data members in the object structure and assigns the address of the memory space to ptr. We can also create an array of objects using pointers Item *ptr = new item[10]; Creates memory space for an array of 10 objects of item. continue…
- 9. 9 Thank You !!! By:-Gourav Kottawar
- 10. 9 Thank You !!! By:-Gourav Kottawar