used in the article

Java-inheritance-demo.java

//Java program to illustrate the 
// concept of inheritance
// https://www.geeksforgeeks.org/inheritance-in-java/
// Demo: https://repl.it/@WillWang42/Java-Class-Inheritance-Demo
 
public class Main
{
  // base class
  static class ClassA 
  {
      public String name;
      
      public ClassA(String name)
      {
          this.name = name;
      }
      
      // the Bicycle class has three methods
      public String print()
      {
          return(name);
      }         
  }
  
  // derived class
  static class ClassB extends ClassA 
  {
      public String surname;
      public ClassB(String name, String surname)
      {
        super(name);
        this.surname = surname;
      }
      
      @Override
      public String print()
      {
          return (super.print()+
                  "\n"+ surname);
      }
  }
  
  public static void main(String args[]) 
  {
      ClassA a = new ClassA("calss A");
      ClassB b = new ClassB("class B","I'm the child");
      System.out.println(a.print()); // class A 
      System.out.println(b.print()); // class B, "I'm the child"
  }
}