OOP Class

  • An Abstraction over a group of similar items that share the same properties and actions

Inner Class

Anonymous Inner Class


Anonymous classes are useful when you need to create a class that implements an OOP Interface or extends a class, but you don’t need to reuse the class elsewhere in your code.

OOP Object

  • An actual instance of OOP Class that occupies some space in the Heap Segment
  • The variable holds a memory pointer to the OOP Object, not the values inside the OOP Object

OOP Interface

  • Defines a set of OOP Abstract Method that a OOP Class must implement if it chooses to implement that interface. It doesn’t provide any concrete implementations for these methods
  • Focus on what a class should do rather than how it should do it

Functional Interface

OOP Method

OOP Abstract Method

  • Methods declared without a body