What are the points noted while deriving a new class?
Answers
Answer:
Derived Class: A class that is created from an existing class. The derived class inherits all members and member functions of a base class. The derived class can have more functionality with respect to the Base class and can easily access the Base class. A Derived class is also called a child class or subclass.
Answer:
Points to Remember:
• The mechanism of deriving new class from an existing class is called inheritance.
• The main advantage of Inheritance is it supports reusability of code.
• The derived class inherits all the properties of the base class. It is a power packed class, as it can add additional attributes and methods and thus enhance its functionality.
• The various types of Inheritance are Single inheritance, multiple inheritance, hierarchical inheritance and hybrid inheritance
• When a derived class inherits only from one base class, it isknown as single inheritance
• When a derived class inherits from multiple base classes itis known as multiple inheritance
• When a class is derived from a class which is a derived class itself – then this is referred to as multilevel inheritance. The transitive nature of inheritance is reflected by this form of inheritance.
• When more than one derived classes are created from a single base class , it is known as Hierarchical inheritance.
• When there is a combination of more than one type of inheritance, it is known as hybrid inheritance.
• In multiple inheritance, the base classes are constructed in the order in which they appear in the declaration of the derived class.
• A sub-class can derive itself publicly, privately or protectedly.
• The private member of a class cannot be inherited .
• In publicly derived class,the public members of the base class remain public and protected members of base class remain protected in derived class.
• In privately derived class, the public and the protected members of the base class become protected in derived class
• In publicly derived class, the public members of the base class remain public
• and protected members of base class remain protected in derived class.
• When class is derived in protected mode, the public and protected members of base class become protected in derived class.
• constructors and destructors of the base class are not inherited but during the creation of an object for derived class the constructors of base class will automatically invoked.
• The destructors are invoked in reverse order .The destructors of the derived classes are invoked first and then the base class.
• size of derived class object=size of all base class data members + size of all data members in derived class
• overriding of the members are resolved by using :: Scope resolution operator.
• this pointer used to refer the current objects members