public class Cinema { private String name; //set via constructor private int seatCount; // set in constructor private int. visibility: With inheritance, the internals of parent classes are often. Composition is another type of relationship between classes that allows one class to contain the other. OOP: Inheritance vs. What type should an array store when using composition over inheritance? When using inheritance, you can create two classes A and B that inherit. Particularly the dangers of inheritance and what is a better way in many cases. An example where you are forced to use inheritance is when you must interact with an external lib that expects a certain type. In inheritance, we define the class which we are inheriting (super class) and most importantly it cannot be changed at runtime. You first create an object, the vehicle; for our case, we have a Benz. 1) uses composition and keeps and inner object so that it doesn't get reinitialized every time. Composition : Since Engine is-part-of Car, the relationship between them is Composition. The Composition is a way to design or implement the "has-a" relationship whereas, the Inheritance implements the "is-a" relationship. ‘Behavior’ composition can be made simpler and easier. มันน่าสนใจดีนะ แต่ผมก็ไม่ค่อยรู้เรื่องมันเท่าไร. Personally I do have a good grasp of understanding this principle, as well as the concepts around it. Inheritance is a core part of what makes object-oriented. or parent class. Usually it implies the opposite. The shown approach is based on the principle of favor composition over inheritance. . Besides that popular frameworks such as JUnit and Spring (there are more) in older version favor inheritance over composition. Inheritance: a class may inherit - use by default - the fields and methods of its superclass. As an experienced Java developer, you are probably aware of all the discussions about composition and inheritance. Composition over inheritance (or composite reuse principle) in object-oriented programming is the principle that classes should achieve polymorphic behavior and code reuse by their composition (by containing instances of other classes that implement the desired functionality) rather than inheritance from a base or parent class Inheritance. # Function. It promotes smaller, more focused classes and smaller inheritance hierarchies. Composition comes with a great deal of flexibility. That does not mean throw out inheritance where it is warranted. Inheritance among concrete types of DTOs is a bad practice. Aggregation: The object exists outside the other, is created outside, so it is passed as an argument (for example) to the constructor. The main difference between inheritance and composition is in the relationship between objects. Effective Java 2nd Edition, Item 16: Favor composition over inheritance: Inheritance is appropriate only in circumstances where the subclass really is a subtype of the superclass. To favor composition over inheritance is a design principle that gives the design higher flexibility. เห็นมีการพูดถึงเรื่อง Composition over Inheritance ใน facebook. Go to react. Composition vs Inheritance Let's quickly explain inheritance. Inheritance is a core part of what makes object-oriented. Composition alone is less powerful than inheritance, because inheritance is composition plus shared behavior plus some other stuff. What advantages does composition have over inheritance? Coupling and Cohesion Ideally, the objects in our system have high cohesion (i. Composition allows other relationships provided in the association. All that without mentioning Amphibious. Inheritance is known as the tightest form of coupling in object-oriented programming. Inheritance gives you all the public and protected methods and variables of the super-class. One of the most common mistakes in software development is the tendency to overuse class inheritance. ซึ่งตัวอย่างที่ชัดเจนก็คือ Java Listener. For example, if order HAS-A line-items, then an order is a whole, and line items are parts. e. This is in continuation of question in link: I am learning the Exception handling in java (basically in inheritance) that child class method must throw the exception which is subclass of parent class method. 2. The bridge pattern is an application of the old advice, “prefer composition over inheritance“. In this tutorial, we’ll explore the differences. Java doesn’t allow multiple inheritance but by using composition we can achieve it easily. You shouldn't have to justify composition over inheritance, but vice versa. They are absolutely different. A composition establishes a “has-a” relationship between classes. Erich Gamma lept onto the software world stage in 1995 as co-author of the best-selling book Design. So in this case, good practice is using inheritance and it allows also to respect the DRY principle. A seminal book. Vector. The circle. AP CS Practice - OOP. Generic classes: Structure, TypeA, TypeB, TypeC, etc. Inheritance is more rigi. This pattern is widely used very handy so inheritance is here to stay. import static net. Types of inheritance in java: a. Inheritance comes with polymorphism. Here we just need to call super of the builder. Use inheritance only when you must and if you need strict contract which subclasses should respect. Composition for Plain Java Classes. It means that one of the objects is a logically larger structure, which contains the other object. When books and articles refer to "prefer composition over inheritance", they are specifically not talking about interfaces; they're talking about state and behaviour inherited from a base class. Just like inheritance, composition allows for code reuse. Favor composition over inheritance is one of the popular object-oriented design principles, which helps to create flexible and maintainable code in Java and other object-oriented languages. In Java, the final keyword can be used to prevent a class from being subclassed. React has a powerful composition model, and we recommend using composition instead of inheritance to reuse code between components. Therefore, intuitively, we can say that all the birds inherit the common features like wings, legs, eyes, etc. So with composition (note this isn't necessarily "Realm" composition, just an example, since it looks like Realm has to use some weird form of interface-composition), I'd have a class like below: public class GermanShepherd { public Animal animal; public Dog dog; // Generate a bunch of delegate methods here }Composition vs inheritance refers to two major concepts in object-oriented programming. Object Adapter uses composition and can wrap classes or interfaces, or both. So we can actually use “Composition over inheritance”. Inheritance is static binding (compile time binding) Composition is dynamic binding (run time binding) Inheritance can denote an "is - a" relationship between classes. I found this statement from the gang of four's "Design Patterns" particularly odd; for some context, the authors are comparing inheritance versus composition as reuse mechanisms [p. Even though both options would work, I feel that going for multiple extensions is preferable since it describes and clarifies the responsibilities of the class. Indeed, this is one of the reasons composition is preferred by some over inheritance; there are no limits on combining functionality (but this isn't the only reason). Though, 1st we need to consider the purpose of inheritance – acquiring common characteristics and behavior, this is useful for building a hierarchy (mentioned interface-like classes also), trees. Instead of inheriting properties and. But those two chapters are pretty general, good advice. ** This *overloads* `setSize`, it doesn't override it. From Effective Java 2nd Edition, Item 16: Favor composition over inheritance: There are a number of obvious violations of this principle in the Java platform libraries. Favoring composition over inheritance increases the flexibility and modularity of your code. Everything is more or less clear with inheritance. Additionally, if your types don’t have an “is a” relationship but. Sorted by: 48. This might mislead to think that there is a relation between these two different concepts: Inheritance is about a relation between classes. From that perspective: there are reasons to use java-esque inheritance, but they're mostly prosaic (i. In statically typed languages where polymorphism is tied to inheritance, that inheritance can be achieved in two ways: one way is stateful and the other way is stateless. "Favor object composition over class inheritance" is actually from GoF book. Share. With Composition pattern, the code is easier to change, and it is less coupled because it is more flexible, so if it is possible favor composition over Inheritance. The following is an example of "composition": public class Car { Engine engine; // Engine is a class } But is it still called "composition" if we are using primitive data. By leveraging composition,. That's a bold statement, considering that reusing implementations is inevitable in inheritance. 4 hours ago · This course is divided into six meticulously crafted sections, each focusing on a core aspect of Object-Oriented Programming: Introduction to OOP: Dive into the basics of OOP, exploring its advantages and disadvantages, and understand the fundamental concepts like Objects, Classes, Abstraction, Encapsulation, Inheritance, and. I am playing around with composition and had a question. 2. g 1. A preview of the full code as in the Intellij is as shown below: The output of the code is derived through composition. We also created an Engine. One of the best practices of Java programming is to “favor composition over inheritance”. Constantly being on the lookout for partners; we encourage. It is usually admitted that extending implementations of an interface through inheritance is not best practice, and that composition (eg. b1 = b1; } public static class BBuilder extends ABuilder { BBuilder () { super (); } } } This solution won't work if parent class has a @Builder annotation as well. The most well known item probably would be Item 16: Favor composition over inheritance. I found this statement from the gang of four's "Design Patterns" particularly odd; for some context, the authors are comparing inheritance versus composition as reuse mechanisms [p. Pros: Reusable code, easy to understand; Cons: Tightly coupled, can be abused, fragile; Composition. Creating deep inheritance hierarchies leads to brittle/inflexible code when you are trying to make changes deep in the hierarchy. Favor Composition over Inheritance. Classes should achieve polymorphic behavior and code reuse by their composition rather than inheritance from a base or parent class. Composition. fromJson (service2. The Inheritance is used to implement the "is-a" relationship. Changing the legacy. The solution to all of these problems is to favor object composition over class inheritance. Classes should achieve polymorphic behavior and code reuse by their composition. What is the best practice when we instantiate an Apple object? Should I construct the fruit object internally without. In OO design, a common advice is to prefer composition over inheritance. Introduction “Favouring composition over inheritance” is something you may have heard about or seen on the web as a principle for object-oriented programming, but what does it mean? There are two basic relationships two classes can have. Composition over inheritance (or composite reuse principle) in object-oriented programming (OOP) is the principle that classes should favor polymorphic behavior and code reuse by their composition (by containing instances of other classes that implement the desired functionality) over inheritance from a base or parent class. In summary: Use Composition when the relationship is “A has an X capability. Both composition and inheritance are object-oriented programming concepts. As such, inheritance breaks encapsulation, as observed previously by Snyder [22]. 1. While they often contain a. หลายๆ ครั้งที่ผมอ่านโค้ดเบสที่เขียนด้วยภาษาที่มีแต่ Object-oriented paradigm ให้ใช้ผมมักจะเจอปัญหาแบบนี้. I would encapsulate all of the business logic into a new class BusinessLogic and have each class that needs BusinessLogic make. While they often contain a. The first example is inheritance while the second is called composition. A might have a C, and pass through methods. However in java 8, default methods. Today we get to take on one of the core items of object-oriented programming, inheritance. In composition, you will no need to Mixin. Simple rules: A "owns" B = Composition : B has no meaning or purpose in the system without A. As an example, let’s consider an application that converts a video from one format to another. Any optimizations enabled by inheritance are incidental. Why use inheritance in java. For example, a car is a kind of vehicle. Composing Functions. It would be even easier to use in Java, if there were language support for delegation. Choosing Inheritance over. You add the behavior to the required class as an internal data field and gain the access to the required set of methods (capabilities) through this field. If you want to reuse code composition is always the right way to go. When people say to prefer composition over inheritance they're not saying you shouldn't use interfaces in languages that have them. If the currently parsed class is not a subclass of a Swing component, the parser will try to find a main (java. Suppose we have a superclass and subclass as follows: ClassC. Composition involves creating classes that contain instances of other classes, rather than extending existing classes. You should favor composition over inheritance. But we can use it in more than one class. I will try to explain the difference between these two by java code examples. Cons: May become complex or clumsy over time if more behavior and relations are added. IS-A relationship is additionally used for code reusability in Java and to avoid code redundancy. One major reason for using composition over inheritance is, that inheritance leads to higher coupling. The composition is a form of ‘has-a’ relationship but viewed as part-of-a-whole’ relation. Javascript doesn't have multiple inheritance* (more on this later), so you can't have C extend both A and B. If all you had in Rust was everything that's in Java, but no inheritance, Rust would be a less capable language. You must have also heard to use Composition over Inheritance. This is typically solved using object composition. 1_ Before implementing. E. it provides non-final public and protected methods, intended to be overridden by subclasses), or it has been designed with composition or delegation in mind (by using the strategy pattern, for example). Others: 1. In delegation, two objects are involved in handling a request: a receiving object delegates operations to its delegate. the new classes, known as derived or child class, take over the attributes and behavior of the pre-existing classes, which are referred to as base classes or super or parent class. ; In the later case, to properly implement A's behaviour, it can be done though composition, making A delegate over some other class/es which do the tasks specified. In languages without multiple inheritance (Java, C#, Visual Basic. Advantages of composition over inheritance in Java. require a java inheritance design tip. a single responsibility) and low coupling with other objects. The approach that most Java shops follow is to avoid inheritance, because it is too complicated, and use composition instead, which also results in lots and lots of mindless code having to be written. According to the design concept, the composition should be preferred over inheritance to get a better level of design flexibility. In this interview, Erich Gamma, co-author of the landmark book, Design Patterns, talks with Bill Venners about two design principles: program to an interface, not an implementation, and favor object composition over class inheritance. Inheritance is an "IS A" relationship, whereas composition is a "HAS A" relationship. In inheritance, you will need to extend classes. Design and document for inheritance or else prohibit it. 1)Inheritance is strongly coupled where as composition is loosely coupled 2) Inheritance is compile time determined where as composition is run-time 3)Inheritance breaks encapsulation where as composition. Composition-based solutions break up a problem into distinct responsibilities and encapsulate the. Aka, its better for you to wrap the sockets retrieved via accept, rather than trying to subclass as you are now. util. Particularly the dangers of inheritance and what is a better way in many cases. It shows how objects communicate with each other and how they use the. Output: Explanation: In above example we have seen that “test” class is extending two classes “Parent1 ” and “Parent2” and its calling function “fun()” which is defined in both parent classes so now here it got confused which definition it should inherit. ” ~ Gang of Four, “Design Patterns”. Jan 9, 2021 Today we get to take on one of the core items of object-oriented programming, inheritance. Our IDEs, like eclipse, allow for easy generation of delegating methods, but the result is terrible code clutter. 4. Java Inheritance Best Practices. Whereas composition allows code reuse even from final classes. Summary. As to why composition is preferred over. */ void setSize(int side); ``` **No. วันนี้มีโอกาสได้เล่าให้น้องในทีมฟังเรื่อง Composition over Inheritance ใน Java Back-end code ถ้า. First question. Inheritance allows an object of the derived type to be used in nearly any circumstance where one would use an object of the base type. However, C# specifically does provide a nice out here. There are several other questions like that out there, most of which got negative votes. The major reason behind having this notion is to use override feature to modify behavior if required and to. Although most of the time we go for an inheritance, when the time comes we should think more critically on this to get the best out of the beauty of the composition. Composition is one of the key concepts of object-oriented programming languages like Java. It might also have a Q, and. If the new class must have the original class. For example, let’s say you are creating various GUI shapes with different colors. This pattern uses Java cloning to copy the. Inheritance is used at its best, when its used to force some features down to its. You may want to prefer inheritance over composition when you want to distinguish semantically between "A is a B" and "A has a B". “Favor composition over inheritance” is a design principle that suggests it’s better to compose. The open closed principle is about changing the behavior without altering the source code of a class. Design Patterns can be divided into: Creational Patterns. When you only want to "copy" functionality, use delegation. This site requires JavaScript to be enabled. By favoring composition, developers can design more robust and extensible applications, leading to cleaner and more scalable codebases. Java, Inheritance is an important pillar of OOP (Object-Oriented Programming). Prefer composition over inheritance as it is more malleable / easy to modify later, but do not use a compose-always approach. Effective Java Item18 - 復合優先於繼承 May 05, 2018. "Favor composition over inheritance" was popularized by the GOF design patterns book, but you need to understand the historical context - in. prefer to work with interfaces for testability. And composition plays very nicely with plain functions than classes. A class that inherits from another class can reuse the methods and fields. However, using implements,. Composition-based solutions break up a problem into distinct responsibilities and encapsulate the. When you want to "copy"/Expose the base class' API, you use inheritance. I usually prefer using Composition over Inheritance, if i do NOT to use all the methods of a class or those methods dont apply to my class. Otherwise, release notes and migration documentation are there to help transitioning from one version of an API to another. . But "composition over inheritance" would say that all of your users should contain a MyConnections instance, not inherit from it. 1. Composition does not allow this. Additionally, if your types don’t have an “is a” relationship but. There have been two key improvements made to interfaces in Java 8 and above, that make the argument for composition even stronger:Convert inheritance to composition in Java; How to access an object in a class in Java; Why favor composition over inheritance; Inheritance vs Composition: Pro's and Cons; Summary: Points to remember; What is composition Composition is a type of relationship between classes where one class contains another, instead of inheriting from another. If the currently parsed class is not a subclass of a Swing component, the parser will try to find a main (java. For example, “A car has an engine”. For me, the composition in Go gives you exactly the same functionality as inheritance in other languages (C++, Java,. enum_dispatch is a crate that implements a very specific optimization, i. Composition does not allow this. Composition and Inheritance both are design techniques. "Summary. That doesn't mean that you should never use inheritance, just. It cannot wrap an interface since by definition it must derive from some base class. Since most languages, including Java, don't allow multiple inheritance, we can opt to extend either one of these classes. 19]: ". you can't change the implementations inherited from parent classes at run-time, because inheritance is defined at compile-time. Mỗi cách thiết kế đều có ưu nhược điểm riêng, chúng ta cần xác định rõ mục đich, và. Summary. Composition. In this example I’ll use JavaScript as it’s one of the most common programming languages at the moment and it can easily show my point. Inheritance inherits the properties of other components, whereas composition merely inherits the behaviour of other components. Let's say that classes are simply virtual tables of methods, and that each object in a language is defined by a reference to a class. 95% of the times instanceof can be replaced with a better design. With composition, it's easy to change. Inheritance is more rigid as most languages do not allow you to derive from more than one type. Today we get to take on one of the core items of object-oriented programming, inheritance. Services. In this article, we have recapped the principle of Composition over Inheritance with an simple example in Java implementation. java. Lastly, anyone who uses inheritance to reuse implementation is doing it wrong. A lot , also has been said about why to avoid inheritance. This conversation with Erich Gamma describes this idea from the book. There's nothing inherently wrong with it, but nowadays there are better solutions - Strategy, Bridge. This is often described as an is-a. Factory pattern - this is quite an architectural issue and this pattern should be the answer for Your problem. For example, if order HAS-A line-items, then an order is a whole and line items are parts; If an order is deleted then all corresponding line items for that order should be deleted. Java; tunchasan / SOLID-Factory Star 42. There is a problem in inheritance: a sub class’s behaviour depends on the implement detail of its super class. The Composition Over Inheritance Principle; The SRP, LSP, Open/Closed, and DIP principles are often bundled together and called SOLID principles. Design for inheritance or prohibit it. 5 Reasons to Prefer Composition over Inheritance in Java On composition, a class, which desires to use the functionality of an existing class, doesn't inherit, instead it holds a reference of that class in a member variable, that’s why the name composition. 6. As an experienced Java developer, you are probably aware of all the discussions about composition and inheritance. Aug 10, 2016. It is a general OOP rule to prefer composition over inheritance, but Kotlin encourages composition even more by making all classes and methods final by. By the end of this article, you. There are still cases where inheritance makes the most sense. The consensus and all the arguments in favour of composition are also valid for JPA. e. from ("myChannel") . “Favor object composition over class inheritance. transform (Transformers. Use non-inheritance composition where you can and inheritance sparingly. In my opinion you can emulate all of the behavior of inheritance via composition. By looking at this code, you can gauge the differences between these two. We can achieve multiple inheritance using composition: Java doesn’t allow multiple inheritance: Composition does not create a hierarchy of classes:. Favoring Composition Over Inheritance In Java With Examples. Inheritance - Functionality of an object is made up of it's own functionality plus functionality from its parent classes. Particularly the dangers of inheritance and what is a better way in many. package com. Advantages of composition over inheritance in Java. For Code Reusability. Composition over inheritance. In addition, ECS obeys the "composition over inheritance principle," providing improved flexibility and helping developers identify entities in a game's scene where all the. Composition is an alternative to inheritance, where a class can. Services. Dairy, Meat, and Produce classes have a generalization relationship with the Item class (inheritance). 9. For the record, I believe your particular case is best solved by composition over inheritance. In addition, ECS obeys the "composition over inheritance principle," providing improved flexibility and helping developers identify entities in a game's scene where all the. Lack of Flexibility, a lot of the time you have a HAS-A relationship over IS-A. Design patterns follow the principle through composition or/and. prefer composition over inheritance ,and so on known articles about the abuse of inheritance. Say I have a Fruit and Apple classes where apple is a passthrough to a fruit. Inheritance can be potent, but it's crucial to use it judiciously. A good example where composition would've been a lot better than inheritance is java. 2. 4. public class Car { //final will make sure engine is initialized private final Engine engine; public Car () { engine = new Engine (); } } class Engine { private String type; }5 Answers. Java restricts a class from having an is a-relation to two (unrelated) classes. But there is no analog of "inner class" in PHP. 類似的主題 在設計模式 中也是再三強調 非常重要. Overview. It depends what you mean by "multiple inheritance" and "composition. From the early days of object oriented programming, there is a practice of using (rather abusing) inheritance. "Java composition is achieved by using instance variables that refers to other objects". No, when people say prefer composition they really mean prefer composition, not never ever ever use inheritance. In my Cinema class I have a Schedule object. Creating deep inheritance hierarchies leads to brittle/inflexible code when you are trying to make. General rule in the OOP is using composition over inheritance. Then recommends to “favour composition over inheritance”. I've actually been slowly drifting away from inheritance to composition over the past few years, and after reading Effective Java, it was the final nail in the inheritance coffin, as it were. g. 3. The Don't Repeat Yourself (DRY) principle is a common principle across programming paradigms, but it is especially important in OOP. ( Added: the original version of question said "use inheritance" for both - a simple typo, but the correction alters the first word of my answer from "No" to "Yes". What are the advantages of inheritance over composition? Ans: One advantage of inheritance is that it can make code more concise and easier to read, as properties and methods can be. First of all, Java 8 introduced Default Methods, which is in fact multi-inheritance in Java. Let's move on. The car is a vehicle. Composition means one object is contained in another object. In this section, we will consider a few problems where developers new to React often reach for. Summary. The main difference: Class Adapter uses inheritance and can only wrap a class. [2] interfaces - Why should I prefer composition over inheritance? - Software Engineering Stack Exchange Why should I prefer composition over inheritance? Asked 11 years, 9 months ago Modified 6 years, 8 months ago Viewed 69k times 138 I always read that composition is to be preferred over inheritance. It is the mechanism in Java by which one class is allowed to inherit the features (fields and methods) of another class. I have heard this favor composition over inheritance again and again in design patterns. Let’s talk about that. One example of this: You want to create a Stack out of a List. g. The Composition over inheritance principle is another important design principle in Java. Summary. a single responsibility) and low coupling with other objects. Learn about Kotlin’s by keyword. Composition is a Has-A relationship. GroceryList class has an aggregation relationship with the Item class (GroceryList is composed of Item objects). Stack, which currently extends java. Stack Exchange Network Stack Exchange network consists of 183 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to. The member objects of your new class are typically private, making them inaccessible to the client programmers who are using the class. Composition over Inheritance: จงขี้เกียจจัดกลุ่ม. I have created a project where I have used composition in some classes. IS-A relationship can simply be achieved by using extends Keyword. If you have a bit of code that relies only on a superclass interface, that. e. Any time you’re given more control over the fine details of something,. Also: In JS, the essence of concatenative inheritance is often masked by the common name “mixins”. 1 Answer. e. In Java, Inheritance means creating new classes based on existing ones. from ("myChannel") . By the way, Composition is also very much preferred in object-oriented design over inheritance, even Joshua Bloch has stated its. Choosing composition over inheritance offers numerous advantages, such as increased flexibility, reduced coupling, and better code maintainability. 2. See full list on baeldung. Composition over Inheritance 意为优先考略组合，而不是继承。有些程序员没懂，有些程序员把它奉为真理与黄金法则。 前日在做游戏开发（和我白天的工作无关，兴趣爱好而已），在对游戏对象建模时，我对这句话有了新的理解。Composition并不总是比Inheritance好。The main disadvantage of Composition is that you need to wrap (duplicate) all the public methods of the private List if you need to present the same interface, in Inheritance you have all of them already available, but you can't override any of them that was made not overridable (in C# it means the method should be marked 'virtual', in Java. The class inheriting from a parent class is called a subclass. What you call "composition from composition" could be the Facade pattern. On the other hand, Composition is the mechanism to reuse code across classes by containing instances of other classes that implement the desired functionality. java - Difference between Inheritance and Composition - Stack Overflow Difference between Inheritance and Composition Ask Question Asked 13 years, 8. Learn about delegation patterns. Bridge Design Pattern in Java Example. For example, for Swing it starts from the constructor of a JPanel or JFrame. E. This is how you get around the lack of multiple inheritance in java. What is composition. What signs I saw that inheritance was starting to t. Composition grants better test. In contrast, Composition is a restricted Aggregation, which means as per aggregation, it allows the relationship between the two classes, but the objects are. Composition. If the base class need to be instantiated then use composition; not inheritance. If The new class is more or less as the original class. Java Inheritance Best Practices. For example, for Swing it starts from the constructor of a JPanel or JFrame. Java: Composition over inheritance Liviu Oprisan 30 subscribers Subscribe 24 Share 1. Sorted by: 48. That's entirely the wrong motivation to base your decision on. Java Inheritance is used for code reuse purposes and the same we can do. What I think is there should be a second check for using inheritance. In this interview, Erich Gamma, co-author of the landmark book, Design Patterns, talks with Bill Venners about two design principles: program to an interface, not an implementation, and favor object composition over class inheritance. Recently I created a YouTube video to explain composition in java in detail, please watch it below.