Java Program to Convert String to Object

Object is the root class of the class hierarchy, so a String can be assigned directly to an Object reference. The actual object remains a String, even though it is referenced through a variable of type Object.

• Assigning a String to an Object reference does not change the String into a different type.
• getClass() can be used to determine the actual runtime type of the object.
• Class.forName() is used to load and obtain metadata about a class from its name; it does not convert a String value into an Object.

Methods To Convert String To Object

1. Using the Assignment Operator

Since String is a subclass of Object, a String can be assigned directly to an Object reference. This is an example of upcasting, where a child-class object is referred to using a parent-class reference.

public class Main {

    public static void main(String[] args) {

        // Create a String
        String str = "GeeksForGeeks";

        // Assign String to an Object reference
        Object object = str;

        // Display the actual class of the object
        System.out.println("Class of object: "
                           + object.getClass().getName());

        // Display the object
        System.out.println("Object: " + object);
    }
}

Class of object: java.lang.String
Object: GeeksForGeeks

Explanation: The String is assigned to an Object reference because String extends Object. The getClass() method confirms that the actual object stored in the reference is still a String.

2. Using Class.forName() Method

The Class.forName() method is used when the name of a class is available as a String and we want to obtain the corresponding Class object.

Syntax

Class.forName(String className);

The method accepts the fully qualified class name as a String and returns a Class object representing that class. If the specified class cannot be found, it throws ClassNotFoundException.

public class Main {

    public static void main(String[] args) {

        try {
            // Class name provided as a String
            String className = "java.lang.String";

            // Get the Class object
            Class<?> classObject = Class.forName(className);

            // Display the class name
            System.out.println("Class name: "
                               + classObject.getName());

            // Display the superclass name
            System.out.println("Superclass name: "
                               + classObject.getSuperclass().getName());

        } catch (ClassNotFoundException e) {
            System.out.println("Class not found: "
                               + e.getMessage());
        }
    }
}

Class name: java.lang.String
Superclass name: java.lang.Object

Explanation: Here, "java.lang.String" is a String containing the name of a class. Class.forName() loads that class and returns a Class object representing String. The getSuperclass() method then shows that String directly extends Object.