publicclassPet{privateStringname；publicPet（Stringname）{this.name=name；}publicvoidspeak（）{System.out.print（name）；}}publicclassDogextendsPet{publicDog（Stringname）{super（name）；}publicvoidspeak（）{super.speak（）；System.out.print（Dog”）；}}执行代码Petpet=newDog（京巴”）；pet.speak（）；后输出的内容是哪项？（）A.京巴B.京巴DogC.nullD.Dog京巴
publicclassPet{privateStringname；publicPet（Stringname）{this.name=name；}publicvoidspeak（）{System.out.print（name）；}}publicclassDogextendsPet{publicDog（Stringname）{super（name）；}publicvoidspeak（）{super.speak（）；System.out.print（Dog”）；}}执行代码Petpet=newDog（京巴”）；pet.speak（）；后输出的内容是哪项？（）
A.京巴
B.京巴Dog
C.null
D.Dog京巴
相关考题：
执行以下代码后，下面哪些描述是正确的（）publicclassStudent{privateStringname=Jema”；publicvoidsetName（Stringname）{this.name=name；}publicStringgetName（）{returnthis.name；}publicstaticvoidmain（String[]args）{Students；System.out.println（s.getName（））；}}A.输出nullB.第10行编译报错C.第11行编译报错D.输出Jema
publicclassEmployee{privateStringname；publicEmployee（Stringname）{this.name=name；}publicvoiddisplay（）{System.out.print（name）；}}publicclassManagerextendsEmployee{privateStringdepartment；publicManager（Stringname，Stringdepartment）{super（name）；this.department=department；}publicvoiddisplay（）{System.out.println（super.display（）+”，”+department）；}}执行语句newManager（smith”，”SALES”）后程序的输出是哪项？（）A.smith，SALESB.null，SALESC.smith，nullD.null，null
publicclassPet{privateStringname；publicPet（）{System.out.print（1）；}publicPet（Stringname）{System.out.print（2）；}}publicclassDogextendsPet{publicDog（）{System.out.print（4）；}publicDog（Stringname）{super（name）；System.out.print（3）；}}执行newDog（棕熊”）；后程序输出是哪项？（）A.33B.13C.23D.123
publicclassEmployee{privateStringname；publicEmployee（Stringname）{this.name=name；}publicStringgetName（）{returnname；}}publicclassManagerextendsEmployee{privateStringdepartment；publicManager（Stringname，Stringdepartment）{this.department=department；super（name）；（应于上一行掉位置）System.out.println（getName（））；}}Super的位置是否在方法的首行执行语句newManager（smith”，”SALES”）后程序的输出是哪项？（）A.smithB.nullC.SALESD.编译错误
类Teacher：classTeacher{Stringname；floatsalary；Teacher（Stringname）{this.name=name；}Teacher（Stringname，floatsalary）{this.name=name；this.salary=salary；}}执行语句Teachert=newTeacher（Tom”，2000.0f）；后，字段salary的值是哪一项？（）A.2000.0fB.0.0fC.null；D.2000
publicclassPerson{2.privateStringname;3.publicPerson(Stringname){this.name=name;}4.publicbooleanequals(Personp){5.returnp.name.equals(this.name);6.}7.}Whichistrue?() A.TheequalsmethoddoesNOTproperlyoverridetheObject.equalsmethod.B.Compilationfailsbecausetheprivateattributep.namecannotbeaccessedinline5.C.Toworkcorrectlywithhash-baseddatastructures，thisclassmustalsoimplementthehashCodemethod.D.WhenaddingPersonobjectstoajava.util.Setcollection，theequalsmethodinline4willpreventduplicates.
publicclassPlant{privateStringname;publicPlant(Stringname){this.name=name;}publicStringgetName(){returnname;}}publicclassTreeextendsPlant{publicvoidgrowFruit(){}publicvoiddropLeaves(){}}Whichistrue?() A.Thecodewillcompilewithoutchanges.B.ThecodewillcompileifpublicTree（）{Plant（）；}isaddedtotheTreeclass.C.ThecodewillcompileifpublicPlant（）{Tree（）；}isaddedtothePlantclass.D.ThecodewillcompileifpublicPlant（）{this（”fern”）；}isaddedtothePlantclass.E.ThecodewillcompileifpublicPlant（）{Plant（”fern”）；}isaddedtothePlantclass.
interface Playable {void play();}interface Bounceable {void play();}interface Rollable extends Playable, Bounceable {Ball ball = new Ball("PingPang");}class Ball implements Rollable {private String name;public String getName() {return name;}public Ball(String name) {this.name = name;}public void play() {ball = new Ball("Football");System.out.println(ball.getName());}}这个错误不容易发现。
Person p = new Person(“张三”,23);这条语句会调用下列哪个构造方法给属性进行初始化() A.public Person(){}B.public Person(String name,int age) { this.name = name; this.age = age; }C.public Person(int age,String name) { this.age = age; this.name = name; }D.public Person(String name) { this.name = name; }