Java Object getClass() Method

The getClass() method in Java is used to obtain the runtime class of an object. It is defined in the Object class and returns a Class object that represents the class of the object.

In this chapter, you will learn about the Java getClass() method, its syntax, return value, and how to use it to obtain information about an object's runtime class.

What is getClass() Method in Java?

The getClass() method is a method of the Object class that returns the runtime class of an object. Since every Java class directly or indirectly inherits from Object, the method can be called on objects of any class.

Syntax

The syntax of object.getClass() method is as follows:

object.getClass()

The method does not accept any arguments and returns a Class<?> object representing the runtime class of the object.

Example of getClass() Method

In the following example, we use the getClass() method to obtain the runtime class of a Student object.

class Student {
}

public class Main {
    public static void main(String[] args) {
        Student student = new Student();

        System.out.println(student.getClass());
    }
}

Output:

class Student

Using getName() with getClass()

The getClass() method returns a Class object, which provides methods such as getName() to obtain the fully qualified name of the class.

Example

In the following example, we use getClass().getName() to get the fully qualified name of the class of an object.

class Student {
}

public class Main {
    public static void main(String[] args) {
        Student student = new Student();

        System.out.println(student.getClass().getName());
    }
}

Output:

Student

getClass() with Inheritance

The getClass() method returns the actual runtime class of an object, not the type of the reference variable used to refer to the object.

Example

In the following example, we use a superclass reference to refer to a Dog object and use getClass() to determine its runtime class.

class Animal {
}

class Dog extends Animal {
}

public class Main {
    public static void main(String[] args) {
        Animal animal = new Dog();

        System.out.println(animal.getClass().getName());
    }
}

Output:

Dog

getClass() vs instanceof

The getClass() method and the instanceof operator can both be used to check the type of an object, but they work differently.