Java Objects and Classes – Learn how to Create & Implement

1. Java Objects and Classes – Learn how to Create & Implement Objects and classes are considered to be the meat and potatoes of any OOPs based language. Since Java is one of the most programming languages it becomes very necessary to know these concepts by heart. Thus, I bring you this article, where I will be giving you a complete overview of Java objects and classes. prominently used Object-oriented Below are the topics covered in this article: What is a Java Class? How to Create a Class in Java? Types of Classes in Java What is an Object in Java? How to Create a Java Object?      Classes and Objects in Java are two such concepts which go hand in hand. You can’t learn one without having the knowledge of the other. Together they form the building blocks of Java. So, let’s quickly jump into the basics and see what actually are Java objects and classes. What is a Java Class? A class in Java is a blueprint from which an object is created. It is a logical entity that helps in defining the behavior and properties of an object. A class can only be accessed from outside via its instance. Every class in Java must belong to some package. Packages in Java are nothing classes, interfaces, and sub–packages. but a group of similar types of The classes in Java are generally classified under two categories: 1. Built-in Classes Built-in classes in Java are the classes which come bundled within predefined packages in Java. Predefined packages are the packages which are developed by Sun MicroSystems and are provided as a part of JDK (Java Development Kit) to help out a java programmer. A few of the majorly used built-in classes are: i. ii. iii. iv. v. vi. vii. viii. ix. java.lang.String java.lang.System java.lang.Exception java.lang.Object java.lang.Class java.util.Date java.util.HashMap java.util.ArrayList java.util.Iterator

2. x. java.lang.Thread 2. User-Defined/ Custom Classes As the name suggests, a custom or user-defined class is a class that is created by a user. It will contain the class members as defined by the user. You will see how to create a class in the next section of this Java objects and classes article. https://www.exltech.in/java-training.html How to Create a Class in Java? A method in Java is a collection of a statement which determines the behavior of a class object. They are generally used to modify the state of a class field. By using methods you can also delegate tasks in other objects. Below I have listed down a few properties of a method: Constructors A constructor in Java is used to initialize an object of a class immediately after the object is created. A constructor must have its name same as its class. In Java, every class has a constructor known as the default constructor but you can add more according to your requirement. Static Block  A static block in Java is the block which is executed only once at the time of class loading. A static block is also known as a static initialization block. A class can have more than one static blocks. https://www.exltech.in/