Composition vs Inheritance in Java
In Java object-oriented programming (OOP), composition and inheritance are important concepts for representing single and multiple relationships between user-defined classes in a program. Therefore, composition and inheritance are helpful techniques for solving problems by repeatedly using program source code multiple times and by breaking large program source code into smaller modules. However, composition and inheritance are used in Java programming for different program scenarios or conditions. This allows Java developers to create flexible and maintainable program source code using composition and inheritance. This allows Java users to better understand how and when to use them.
So, let’s better understand the main differences between composition and inheritance in Java.
Inheritance in Java.
The concept of inheritance in Java programming is a built-in feature of OOP, in which a user-defined class (known as a subclass or derived class declared in the main class) inherits the default properties and behavior (class fields and custom user-defined methods) of another class (known as a superclass or base main class) and uses them. Inheritance represents the subclass to superclass in a tree structure. This means that the subclass defined in the class is a user-defined type of the main superclass.
Example of the Java inheritance concept.
class Course {
public void select_course() {
System.out.println(“You can select your desired course with select_course”);
}
}
class Java extends Course {
public void select_course() {
System.out.println(“Java select”);
}
}
public class Main {
public static void main(String[] args) {
Java java = new Java();
java.select_course(); // Here we implement Java course select
}
}
An example of the Java inheritance concept.
- Here, in the inheritance class program, Java inherits the select_course() behavior from Course.
- Here, in the inheritance concept, we see that Java is a subclass of the Course class, because the Java subclass extends the Course superclass.
Advantages of inheritance in Java programming.
- Code reusability – In Java user-defined class programs, inheritance features allow subclasses to reuse the source code of the superclass, avoiding the concept of duplication of programmer-defined source code.
- Ease of maintenance – With the inheritance concept, any modifications made to the superclass are automatically inherited by the subclass. are.
- Extensibility – Inheritance features allow a new class behavior to be created by creating a subclass from a superclass.
Disadvantages of inheritance in Java programming.
- Tight coupling – Subclasses defined in Java classes are strongly grouped with the superclass, meaning that any modifications to the superclass can have an immediate impact on the subclass.
- Limited flexibility – Remember, a user-created subclass inherits properties and features from only one superclass, making grouping features from multiple classes complex. Java programming does not support multiple inheritance features for a class.
- Can have an inflexible hierarchy – As the inheritance hierarchy of superclass and subclass features grows in a Java class program, modifying and maintaining large, millions of lines of program source code can become very complex. Especially if you are designing and passing subclasses from superclasses to subclasses in a detailed nested class. Developing.
Java Composition Features.
Composition features are a design method or concept in Java class programming, in which a user-defined class is composed of one or more objects of another class. Java composition features are used to demonstrate class-object relationships. One class defines references to other classes, and delegates tasks to these group class objects. This is often referred to as a “has-a” concept, because a superclass or other class defines instances of other classes.
Example of Java Composition Features.
class Exercise {
public void run() {
System.out.println(“Start exercise”);
}
}
class Fit {
private Exercise exercise; // here we define Fit class has an Exercise class
public Fit() {
exercise = new Exercise(); // here we Composing Fit with Exercise
}
public void youwillfit() {
exercise.run(); // here we Delegating the run behavior to Exercise class
System.out.println(“You will be Fit now”);
}
}
public class Main {
public static void main(String[] args) {
Fit fit = new Fit();
fit.youwillfit();
}
}
Example of Java Composition Features.
- Here, the Fit subclass has an Exercise superclass. The Fit class is derived from the Exercise class, and it creates an Exercise object to run the exercise.
Advantages of Composition in Java.
- Loose Coupling – Composition features in Java provide greater flexibility and loose coupling within existing classes. Any modifications to existing group classes (e.g., Exercise) do not directly impact the included class (Fit).
- Flexibility – A class can create instances of multiple other classes, giving the user greater flexibility in class development. For example, a Fit class can contain instances of Exercise, Transformation, Health, etc.
- Easy to modify – If the default behavior of a class program needs to be modified, Java users can simply replace or replace composed class objects instead of updating a class hierarchy. For example, an Exercise class can be modified with another type of Exercise if needed.
- Reuse – These implement existing class composition, and Java users can use these objects multiple times if needed. This is useful for multiple classes in a class program.
Disadvantages of Composition in Java.
- More boilerplate code – Java composition features can create more program source code, requiring Java users to manually create and manage the associated class objects. This is a manually complex process.
- Object management – Java users must manually manage the lifecycle of composed class objects in large code bases. Due to which beginner Java users may face complexity in some particular conditions.
