Difference Between Class and Object in Java
Java is one of the most popular programming languages in the world, renowned for its robustness, flexibility, and powerful capabilities. One of the most fundamental concepts of Java programming involves the distinction between classes and objects. Both are integral to the Java programming language, but they serve different purposes and have different functions. In this article, we’ll explore the main differences between classes and objects in Java.
What Is a Class in Java?
A class is a blueprint or template for creating objects. It defines a set of attributes and methods that can be applied to objects created from that class. Essentially, a class is a blueprint for objects, which specify how objects of that type behave and what operations can be performed on them. For example, the Java String class defines how strings are created and manipulated, while the Java Integer class defines how integers are created and manipulated.
In Java, classes provide encapsulation, inheritance, and polymorphism. Encapsulation means that a class can hide its internal workings and limit access to its attributes and methods. Inheritance refers to the way that subclasses can inherit attributes and methods from their parent classes. Polymorphism means that objects of different types can be treated as if they are of the same type, allowing for flexibility and abstraction.
What Is an Object in Java?
In Java, an object is an instance of a class. Objects are created by declaring and instantiating a class using the new keyword. An object is an entity that can have attributes and methods, just like a class. However, objects are specific instances of a class, while classes are general templates or blueprints.
For example, an object created from the Java String class might have the attributes “length” and “value” and the methods “concat” and “substring”. An object of the Java Integer class might have the attributes “intValue” and “MAX_VALUE” and the methods “parseInt” and “toBinaryString”.
The Main Differences between Class and Object in Java
The main differences between classes and objects in Java are:
– A class is a template or a blueprint for creating objects, while an object is an instance of a class.
– A class defines attributes and methods that can be applied to objects, while an object has specific values for those attributes and can perform specific operations on those methods.
– A class is a static entity, while an object is a dynamic entity that can change over time.
– Classes provide encapsulation, inheritance, and polymorphism, while objects provide specific instances of those abilities.
In conclusion, understanding the difference between classes and objects is essential to learn and master Java programming. Classes define how objects behave and what operations can be performed on them, while objects are specific instances of those classes that have particular values for their attributes and methods. By understanding the distinction between classes and objects, you can develop robust, flexible, and powerful Java programs that meet your specific needs.
Table difference between class and object in java
| Class | Object |
|---|---|
| A blueprint or template used to create objects | An instance of a class created using the new keyword |
| Defines the attributes and behaviors of an object | Has its own set of attributes and behaviors defined by its class |
| Can be abstract or concrete | Concrete, as it represents a specific instance of a class |
| Can be extended to create new subclasses | Cannot be extended or subclassed |
| Can have static members and methods | Cannot have static members or methods |