// code to illustrate using reflection to change data at runtime

import java.lang.reflect.Field;

class Student {
  private String firstName = "Sampath";
}

public class TestReflection {
  public static void main(String args[]) throws Exception {
    Student someStudent = new Student();
        
    Field fs = someStudent.getClass().getDeclaredField("firstName");
    fs.setAccessible(true);

    System.out.println("Value of " + fs.getName() + ": " + fs.get(someStudent));

    fs.set(someStudent, "Trisha");
    System.out.println("Value of " + fs.getName()
                       + " after changing: " + fs.get(someStudent));
  }
}

// OUTPUT:
//Value of firstName: Sampath
//Value of firstName after changing: Trisha

// this feature is useful in serialization, support for FXML, etc.