class Human{ public static void walk() { System.out.println("Human walks"); } } class Boy extends Human{ public static void walk(){ System.out.println("Boy walks"); } public static void main( String args[]) { /* Reference is of Human type and object is * Boy type */ Human obj = new Boy(); /* Reference is of HUman type and object is * of Human type. */ Human obj2 = new Human(); obj.walk(); obj2.walk(); } }