Subtyping

A value of a subtype can be substituted for a value of a supertype.

Related concepts:  TypePolymorphismInheritance

Closest Wikipedia entry:  Subtyping

Misconceptions about Subtyping

11 documented Misconceptions

CallNotStaticallyChecked

A method invocation on a reference of a type that does not have that method won't compile

ConcreteClassOnlyImplementClassAbstract

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

ConcreteClassOnlyImplementDirectAbstract

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

ConcreteClassOnlyImplementInterfaceAbstract

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

ExceptionRoot

Exception is the top-most exception class

InterfaceExtendClass

An interface can extend a class

MultipleSuperclasses

A class can have multiple superclasses

RuntimeExceptionChecked

RuntimeExceptions are checked exceptions

StaticDispatch

The method to be called is determined by the static type

SubtypeCompatibleWithSupertype

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

SupertypeIncompatibleWithSubtype

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