Class,Abstract class,InterfaceI. Class publicclassDemoJavaBasic {}classDemo {privateStringname;publicvoidstudy() { }} Trong mt Class ch nn c mt Public class Lp cha cc thuc tnh v cc phng thc hot ng ca i tng Khai bo lp : class { attribute + method }Tnh cht + Public lp ny c th c truy cp t cc gi+ Final khng to dn xut(Khng c s k tha)+ abstract : Ch cha phng thc tru tng,khng to c cc Instance bng ton t New1. Thuc tnh ca lp Kiu d liu : Do ngi dng nh ngha,c trc int,String..Tnh Cht : Mc nh public truy cp t bn ngoi Protected : Truy cp t lp nh ngha,cc lp k tha t lp Private : Truy cp bn thn lp nh ngha Static : Dng cho mt th hin ca lp. C th truy cp trc tip bng . m khng cn khi to mt th hin ca lp New Abstract : nh ngha thuc tnh tra tng,khng th truy nhp trong lp nhng c th b nh ngha cc lp k tha Final : Thuc tnh hng, khng b nh ngha chng cc lp k. Native Synchronized : 2. Phng thc ca lp ([Cc than s]){ Operater }Tnh cht : Ging thuc tnh (Public,Private,Protected,static,final)Kiu tr v : String,int+ngi dng t nh ngha..3. Hm khi to Tn trng tn vi lp Khng c gi tr tr v Tnh cht public C tham s hoc khng c tham s c gi n bng cch dng t kha NEW C construc khi to mc nh.Public ([C hoc khng c tham s]){ Nu c th gn} This : Lun tn ti trong cc lp Java Tr n bn thn ca lp m cha n. Dng trong cc hm khi ta,set.Public (String name,int age){ this.name = name; //this.name chnh l thuc tnh ca class m n tr tithis.age = age; //this.age chnh l thuc tnh ca class m n tr ti}II. InterfaceinterfacePerson {publicstaticfinalStringCOUNTTRY_NAME=Viet Nam;publicabstractvoidshow1();} Gm ba thnh phn : T kha Interface Tn Interface Thn Interface : C hai thnh phn+ Thuc tnhl (Static v final) : Thuc tnh c nh nh sauPublic static final [Kiu d liu ] [Tn bin ]=[Gi tr];publicstaticfinalStringCOUNTTRY_NAME=Viet Nam;+ Phng thc (public v abstract )Phng thc kt thc du; Phng thc abstract.publicvoidshow();III. Abstrac classabstractclass Employee{privateStringname;publicvoidstudy() { }publicabstractvoidmove();} Ba thnh phn T kha abstract class Tn abstract class Thn abstract class : C hai thnh phn+ Thuc tnh+ Phng thc : C hai cch khai bo1. Khai bo nh classpublicvoidstudy() { body }

2. Khai bo ging interface + abstractpublicabstractvoidmove();Ch : Nu phng thc khai bo Public abstract ();Th phi t n vo trong lp tru tng abstract class .KT LUN Class th l ta dng trc tip lun cc phng thc v thuc tnh Interface,Abstrac xy dng chun b cho vic s dng khi cn s dng th ta Implement vo.