Aggregation in Java

Aggregation in Java

If a class in java has entity reference, that is called aggregation.Think of a situation where an employee has name, has ID and has an Address which contains information such as Address, City, State etc. which is contained in class Address.This means class Employee  HAS-A address.

Example Code

public class Employee {
    String name;
    int id;
    Address address;
    
}

Class Address

public class Address {
    String city;
    String state;
    int zip_code;
    String street_name;
    
}

Why Aggregation in java
The main reason for using aggregation in java is to enable code reuse.