What is whole part relationship in Java?

Aggregation in Java is a relationship between two classes that is best described as a “has-a” and “whole/part” relationship. … The aggregate class contains a reference to another class and is said to have ownership of that class. Each class referenced is considered to be part-of the aggregate class.

In OOP, IS-A relationship is completely inheritance . This means, that the child class is a type of parent class. For example, an apple is a fruit. So you will extend fruit to get apple.

In Java, we have two types of relationship: Is-A relationship: Whenever one class inherits another class, it is called an IS-A relationship. Has-A relationship: Whenever an instance of one class is used in another class, it is called HAS-A relationship.