Object-oriented programming in Java is a powerful and popular tool for developing applications and software systems. With its wide range of features and capabilities, it is no surprise that it has become the language of choice for many developers. This comprehensive guide will give you an in-depth look at the fundamental concepts of object-oriented programming in Java, from classes and objects to inheritance and abstraction. With this guide, you will be on your way to becoming a proficient Java programmer, capable of creating robust and efficient applications.
Keys Points To Remember About A Constructor In Object Oriented Programming
1.A constructor is a member method.
2. It has the same name as the class name.
3. It will never return anything.
4. It tells us how much space in memory needs to be allocated for an object.

Now let’s see why we even need to make our class as final. Let’s say, we have 3 classes, first is the Main class, second is the Car class (child class) and third is the Vehicle class (It is a parent class. The vehicles can represent cars, bikes, trucks, etc).
The Vehicle class has a method called accelerate() using which our vehicles will move. Our Car class also wants to implement such a method so that our cars can move. But implementing the same thing again which is already present is not a good idea. So, in java, there is something called inheritance using which we can inherit the properties of the other class and access them inside our own class. This is done with the help of the extend keyword.