What is the difference between association, aggregation and composition?

Question

What is the difference between association, aggregation, and composition? Please explain in terms of implementation.

Answer 1

https://www.linkedin.com/pulse/types-relationships-object-oriented-programming-oop-sarah-el-dawody/

Composition: is a "part-of" relationship.

for example “engine is part of the car”, “heart is part of the body”.

Association: is a “has-a” type relationship

For example, suppose we have two classes then these two classes are said to be “has-a” relationships if both of these entities share each other’s object for some work and at the same time they can exist without each other's dependency or both have their own lifetime.

The above example showing an association relationship because of both Employee and Manager class using the object of each other and both their own independent life cycle.

Aggregation: is based is on "has-a" relationship and it's is \\a special form of association

for example, “Student” and “address”. Each student must have an address so the relationship between Student class and Address class will be “Has-A” type relationship but vice versa is not true.