Three kinds of relationships between classes

Objective

The implementation of a program often involves multiple classes, and classes are often " related " to classes. This article describes the three most common and classic relationships between classes.

Dependency Uses-a

This is the most obvious and most common kind of relationship. If a method of a class needs to manipulate the object of another class , we say that one class depends on another class.

Common examples are order classes and account classes in order systems, because order classes require access to the account class to view their credit status.

We should make this relationship the least class, and even the least coupling between classes.

Aggregation Relationship Has-a

This is the best understanding of a relationship where the object of one class contains an object of another class , and we say that one class is aggregated to another class.

Inheritance Relationship Is-a

This is a special and general relationship, and if one class inherits another, it says that these two classes are inheritance/parent-child relationships.

Three kinds of relationships between classes