Inheritance

Inheritance is a way to define a class by reusing the definition of another class.

Related concepts:  ClassMemberSubtyping

Closest Wikipedia entry:  Inheritance (object-oriented programming) — In object-oriented programming, inheritance is the mechanism of basing an object or class upon another object (prototype-based inheritance) or class (class-based inheritance), retaining similar implementation. Also defined as deriving new classes (sub classes) from existing ones such as super class or base class and then forming them into a hierarchy of classes. In most class-based object-oriented languages like C++, an object created through inheritance, a "child object", acquires all the properties and behaviors of the "parent object", with the exception of: constructors, destructors, overloaded operators and friend functions of the base class.

Misconceptions about Inheritance

16 documented Misconceptions

AbstractClassMustImplementAbstractMethod — Java

An abstract class must implement all abstract methods defined in its superclass

AbstractClassNoImplementation — Java

An abstract class cannot contain implemented methods

ConcreteClassMustOverride — Java

A concrete class needs to implement all methods declared in its abstract superclasses

ConcreteClassOnlyImplementClassAbstract — Java

A concrete class only needs to implement those abstract methods it inherits from abstract superclasses

ConcreteClassOnlyImplementDirectAbstract — Java

A concrete class only needs to implement abstract methods declared in its direct supertypes

ConcreteClassOnlyImplementInterfaceAbstract — Java

A concrete class only needs to implement those abstract methods it inherits from interfaces

ImplicitInterfaceImplementation — Java

Java implicitly produces implementations of any methods a class inherits from the interfaces it implements

InterfaceExtendClass — Java

An interface can extend a class

NoMethodInheritance — Java

Subclasses inherit fields but not methods

PrivateAccessibleInSubclass — Java

Private members of a superclass are accessible from a subclass

StaticDispatch — Java

The method to be called is determined by the static type

SubtypeCompatibleWithSupertype — Java

A variable of a subtype can reference an object of a supertype

SuperAlwaysHasParentheses — Java

To call a method on a superclass, parentheses are needed after the keyword super

SuperNotFirstStatement — Java

super() can be called anywhere in the constructor of a subclass

SuperclassObjectAllocated — Java

When instantiating an object of a subclass, an object of a superclass is also allocated

SupertypeIncompatibleWithSubtype — Java

A variable of a supertype cannot reference an object of a subtype