single-inheritance.java

class Employee {
  String name;
  Integer salary;
  
  public Employee() {
   name = "Daniel";
   salary = 120000;
  }
  
  public void printDetails(){ 
    System.out.println(name + " " + salary);
  }
}

class JavaEngineer extends Employee {
  String language;

  public JavaEngineer() {
   language = "Java";
  }
  
  public void printLanguage(){ 
    System.out.println(language);
  }
}

public class TestInheritance {
    public static void main(String ... args) {
          JavaEngineer javaEngineer = new JavaEngineer();
          javaEngineer.printDetails(); // Daniel 120000
          javaEngineer.printLanguage(); // Java
    }
}