Object class in Java

The Object class is the parent class of all the classes in java by default. In other words, it is the topmost class of java.

The Object class is beneficial if you want to refer any object whose type you don't know. Notice that parent class reference variable can refer the child class object, know as upcasting.

Let's take an example, there is getObject() method that returns an object but it can be of any type like Employee,Student etc, we can use Object class reference to refer that object. For example:

The Object class provides some common behaviors to all the objects such as object can be compared, object can be cloned, object can be notified etc.

public class Object

The Object class is the root class in Java from which every class implicitly inherits.

Syntax

Here is the syntax:

Constructor Summary

The Object class provides a default constructor to create a new object instance.

Syntax

The following is the syntax of invoking default constructor of Object class:

Constructor Detail

The constructor of the Object class has no parameters and initializes a new instance of the object.

Syntax

The following is the syntax of constructor detail:

Methods of Object class

The following tables lists the commonly used methods of object class:

Examples of Object Class Methods

Here are examples of commonly used methods of the Object class:

Example 1: Use of toString() Method

The following example demonstrates the toString() method that returns a string representation of the object:

Output:

Object as String: java.lang.Object@1b6d3586

Example 2: Use of equals() Method

The following example demonstrates the equals() method that checks whether two objects are equal:

Output:

Are the strings equal? True

Example 3: Use of hashCode() Method

The following example demonstrates the hashCode() method that returns the hash code value of an object.

Output:

Hash code of the object: 460141958