| An object is a distinct instance of its class (an actual occurrence). It has its own set of variables (known as "instance variables") and methods (known as "instance methods"). When called, an object's instance methods automatically act upon its instance variables Java program creates many objects from a variety of classes. |
| These objects interact with one another by sending each other messages. Through these object interactions, a Java program can implement a GUI, run an animation, or send and receive information over a network. Once an object has completed the work for which it was created, it is garbage-collected and its resources are recycled for use by other objects. |
| Creating Objects |
| In Java, we create an object by creating an instance of a class or, in other words, instantiating a class. |
| Ex: |
| Rectangle rect = new Rectangle(); |
| The above single statement performs three actions: |
| 1. Declaration: Rectangle rect is a variable declaration that declares to the compiler that the name rect will be used to refer to a Rectangle object. Here a class name is used as the variable's type. |
| 2. Instantiation: new is a Java operator that creates the new object (allocates space for it). |
| 3. Initialization: Rectangle() is a call to Rectangle's constructor, which initializes the object. |
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