Transformation of JAVA objects

/*Object Transformation: 1, the object's upward transformation subclass to the parent class by default to the parent class reference to the Subclass object 2, the object's downward transformation parent class to the subclass coercion keyword: instanceof test whether the left object is an instance of the right class if it is return true is not return false*/classanimal{voidsleep () {System.out.println ("Sleeping in"); }}classCatextendsanimal{voidCatchmouse () {System.out.println ("Rat catcher."); }}classDogextendsanimal{} Public classtest{ Public Static voidMain (string[] args) {Animal a=NewCat ();//an upward transformation of an objectCat C= (Cat) A;//Object-down transformationC.catchmouse (); }}

Transformation of JAVA objects