abstract class in java

Java interface and abstract class small notes@author IxenosInterface 1. The interface does not have a constructor because the interface is not instantiated2. Anonymous objects if the constructor that uses the interface also simply represents a covariant anonymous object that implements the interface3. The member variables in the interface are the public sta

;publicstaticfinal that belongs to graphic class doublepi=3.14;publiccircle (Stringname,doubler) {super (name); THIS.R =r;} The area of Publicvoidgetarea () {System.out.println (name+) is: "+pi*r*r);} The perimeter of Publicvoidgetlength () {System.out.println (name+) is: ' +2*pi*r ';}} Rectangle belongs to the one classrectextendsmyshape{intwidth;intheight;public in the graph Rect (StrIngname,intwidth,intheight) {super (name);this.width=width;this.

(P.kouhao ());Ten } One //System.out.println (A.kouhao ()); A //System.out.println (B.kouhao ()); - - } the - - } - + Abstract classperson{ - PrivateString name; + PublicPerson (String aname) { A This. name=Aname; at } - PublicString GetName () { - return This. Name; - } - Public AbstractString Kouhao (); - } in - classEmployee extends person{ to PrivateString Alaname; + PublicEmp

Abstract class animal{???? Public abstractvoid eat (); }class Dog extends animal{ ???? Public void eat () { ???????? System. out. println (" The dog eats bones . ");????}}class Cat extends animal{ ???? Public void eat () { ???????? System. out. println (" The cat eats the mouse ");????}}

One.There is also a part of inheritance called abstract class.Why abstract classes are present, for instance., Demoa and demob two classes have the same method, and if there is no inheritance relationship between them, they can be extracted upward. After extraction, subclasses inherit the parent class. and the contents of the subclass can be omitted to write, the

("End of Battle");} abstract void Attack ();p ublic Void Action () {//Action template Ready (); attack (); end ();}} Class Landsoldier extends Soldier{public landsoldier (String name) {super (name);} public void Attack () {System.out.println ("Army Soldier" +getname () + "start Attack");}} Class Oceansoldier extends Soldier{public oceansoldier (String name) {sup

In object-oriented concepts, all objects are depicted by classes, but conversely, not all classes are used to depict objects, and if a class does not contain enough information to depict a specific object, such a class is an abstract class.Abstract classes In addition to the object cannot be instantiated, other functions of the

barking, but how to make sure, this method teaches abstraction.When a class describes a thing, there is not enough information to describe the thing, and this class is abstract.Abstract class Canine {abstract void sing ();//four legs, two eyes, running, jumping ...} Class D

Not much to say, the first paragraph of code. Public classabstract{ Public Static voidMain (string[] args) {Cl2 c=NewCl2 (); C.method (); }}Abstract classabc{ Public Abstract voidmethod (); }classCl2extendsabc{ Public voidmethod () {System.out.println ("Concrete Method"); }}There can be no abstract method in an abstract