Introduction to Object Class

This section describe about Object Class and it's implementation in java.

Introduction to Object Class

Objects basics

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Object Class

• All the classes defined are subclasses by default.
• Object class is superclass of every class.
• The inheritance happens automatically.
• Your classes will inherit members from the class Object.

Given below some methods and their functions :

Example :Getting class name of the object

class Sub {
	public Sub(String myname) {
	}
}

public class ObjectClass {
	public static void main(String args[]) {
		Sub s = new Sub("Ankit");
		Class classname = s.getClass();
		System.out.println(classname.getName());
	}
}

Output :

Comparing Objects

In java, objects can be compared using 'equals' method as :

public class EmployeeMain {
	public static void main(String[] args) {
		Employee emp1 = new Employee("Divya", "Singh");
		Employee emp2 = new Employee("Ankit", "Kaushal");
		if (emp1.equals(emp2))
			System.out.println("These employees are the same.");
		else
			System.out.println("These are different employees.");
	}

}

class Employee {
	private String lastName;

	private String firstName;

	public Employee(String lastName, String firstName) {
		this.lastName = lastName;
		this.firstName = firstName;
	}

	public String getLastName() {
		return this.lastName;
	}

	public String getFirstName() {
		return this.firstName;
	}

	public boolean equals(Object obj)

	{
		if (this == obj)
			return true;
		if (this == null)
			return false;

		if (this.getClass() != obj.getClass())
			return false;

		Employee emp = (Employee) obj;
		return this.lastName.equals(emp.getLastName())
				&& this.firstName.equals(emp.getFirstName());
	}
}

Output :

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