Abstract classes and Concrete classes

/*2. Abstract classes and Concrete classes
* Abstract can be used to define classes and methods
* Abstract method without method body */

1 Abstract classanimals{2 String name;3 String food;4     5      Public Abstract voideat ();6      Public Abstract voidroam ();7     8 }9 Ten Abstract classCanineextendsanimals{ One     //canine do not necessarily implement the method of parent class animal A      Public voideat () { -System.out.println ("Dog animals are eating!") "); -     } the } -  Public classTwochouextendscanine{ -     //because Twochou is not an abstract class, it implements a method that the parent class does not implement in the subclass . -     //If the Eat method is implemented here, the Eat method is rewritten +      Public voidRoam () { -System.out.println ("The dog likes Sahuan to run!") "); +     } A      Public Static voidMain (string[] args) { atTwochou d =NewTwochou (); - d.eat (); - D.roam (); -     } -}

Abstract classes and Concrete classes