javaoop复习题

笔试题1.给定如下java代码,下列()方法可以加入到Smaple类中,并且能够编译正确.(选两项)publicclassSample{publicintgetSomething(intd){returnd;}}A.privateintgetSomething(inti,Strings);B.publicvoidgetSomething(inti);C.privateintgetSomething(byteb){returnb;}D.publicdoublegetSomething(){return2;}2.给定如下java代码,编译运行后,结果是(b)publicclassSample{privateintx;publicSample(){x=1;}publicvoidSample(doublef){this.x=(int)f;}publicintgetX(){returnx;}publicstaticvoidmain(String[]args){Samples=newSample(5.2);System.out.println(s.getX());}}A.发生编译错误,编译器提示:出现重复方法SampleB.发生编译错误,编译器提示:未定义构造方法Sample(double)C.正常运行,输出5.2D.正常运行,输出53.给定如下java代码,编译运行后,将会输出()结果.publicclassSample{publicdoubleresult(doubled1,doubled2){returnd1d2?d1:d2;}publicdoubleresult(intd1,doubled2){returnd1d2?d1:d2;}publicintresult(intd1,intd2){returnd1-d2;}privateintresult(inti){returnI;}publicstaticvoidmain(Stringargs[]){Samples=newSample();System.out.print(s.result(2,3.0)+”,”);System.out.print(s.result(4.0,4.5)+”,”);System.out.print(s.result(10,9));}}A.3.0,4.0,1B.2,4.0,1C.3.0,4.5,-1D.-1,4.0,14.构成方法重载的要素包括().(选三项)A.方法名称相同B.返回类型不同C.参数列表不同D.在同一个类中5.在如下所示的Sample类中,共有()个构造方法publicclassSample{privateintx;publicSample(){x=1;}publicvoidSample(doublef){this.x=(int)f;}publicSample(){x=2;}publicSample(Strings){}}A.4B.3C.2D.16.给出下列java代码,请指出代码中存在的错误().(选两项)classTeacher1{publicTecher1(){}}classTeacher2{publicvoidTeacher2(Stringname){}}publicclassTeacherTest{publicstaticvoidmain(String[]args){Teacher1t1=newTeacher1();Teacher2t2=newTeacher2(“MrLee”);}}A.Teacher1类中的构造方法名称与类名不相同B.Teacher2类中为定义Teacher2(Stringname)构造方法C.测试类中的代码:Teacher1t1=newTeacher1();不能编译通过D.没有错误7.给定如下java代码,下列()方法可以加入到Child类中,并能够保证编译正确.classBase{publicvoidmethod(){}}classChildextendsBase{}A.publicvoidmethod(Strings){}B.publicintmethod(){return1;}C.privatevoidmethod(){}8.编译运行如下java代码,以下说法正确的是()classBase{privateStringname;publicBase(){name=“Base”;}publicvoidmethod(){System.out.println(name);}}classChildextendsBase{publicChild(){super(“Child”);name=”CC”;}}publicclassSample{publicstaticvoidmain(String[]args){Chlildc=newChild();c.method();}}A.发生编译错误B.正常运行,输出:BaseC.正常运行,输出:ChildD.正常运行,输出:CC9.在子类的构造方法中,使用()关键字调用父类的构造方法A.baseB.superC.thisD.extends10.构成方法重写的要素不包括().(选两项)A.方法名称相同B.返回类型相同C.参数列表相同D.在同一个类中E.存在子类和父类中F.返回类型不同11.编译运行下列java代码,输出结果是()publicclassSample{publicstaticvoidmain(String[]args){Childc=newChild();c.method();}}classBaseextendsObject{privateStringname;publicBase(){name=”Baseconstructor”;}publicBase(StringpName){name=pName;}publicvoidmethod(){System.out.println(name);}}calssChildextendsBase{publicvoidmethod(){System.out.println(“Childmethod”);}publicChild(){super(“Childconstructor”);}}A.BaseconstructorB.ChildconstructorC.Childmethod12.下面的程序中定义了一个java接口,其中包含()处错误publicinterfaceUtility{privateintMAX_SIZE=20;intMIN_SIZE=10;voidUse(){System.out.println(“usingit”);}privateintgetSize();voidsetSize(inti);}A.1B.2C.3D.413.给定如下java代码,可以填入下划线处的语句是().(选三项)publicinterfaceUtility{}classFourWheelerinplementsUtility{}classCarextendsFourWheeler{}classBusextendsFoourWheeler{}publicclassTest{publicstaticvoidmain(String[]args){_________}}A.Utilitycar=newCar();B.FourWheelerbus=newBus();C.Utilityut=newUtility();D.Busbus=newFourWheeler();E.FourWheelerfw=newFourWheeler();14.以下()修饰符用于声明一个类变量,且该变量的值在运行期间恒定不变.A.staticB.finalC.staticfinalD.finalstatic15.给定下列java代码,可以填入下划线处的语句是()publicinterfaceConstants{intMAX=50;intMIN=1;}pulbicclassTest{publicstaticvoidmain(String[]args){_________}}A.Constantscon=newConstants();B.Constants.MAX=100;C.inti=Constants.MAX-Constants.MIN;D.Constants.MIN0;16.公有成员变量MAX是一个int型值,变量的值保持参数值100，在类Constants中,可以使用以下()声明语句来定义这个变量.A.publicintMAX=100;B.finalintMAX=100;C.publicstaticintMAX=100;D.publicfinalintMAX=100;17.能单独和finally语句一起使用的块是()a.tryb.catchc.throwd.throws18.下面的程序执行结果是()publicclassTest{publicstaticvoidmain(String[]args){newTest().test();}publidvoidtest(){try{System.out.print(“try”);}catch(ArrayIndexOfBoundsExceptione){System.out.print(“catch1”);}catch(Exceptione){System.out.print(“catch2”);}finally{System.out.println(“finally”);}}}A.tryfinallyB.trycatch1finallyC.trycatch2finallyD.finally19.下面代码正确的是()A.try{System.out.print(“try”);}catch(Exceptione){System.out.print(“catch”);}B.try{System.out.print(“try”);}C.try{System.out.print(“try”);}finally(Exceptione){System.out.print(“finally”);}Dtry{System.out.print(“try”);}finally{System.out.print(“finally”);}20.下面的程序的执行结果是()publicclassTest{publicstaticvoidfoo(){try{Strings=null;Strings2=s.toLowerCase();}catch(NulllPointerExceptione){System.out.print(“2”);}finally{System.out.print(“3”);}System.out.print(“4”);}}publicstaticvoidmain(String[]args){foo();}a.2b.34c.23d.23421.下列类中在多重catch中同时使用时,()异常类应该最后列出a.ArithmeticExceptionb.NumberFormatExceptionc.Exceptiond.ArrayIndexOutOfBoundsException22.下面关于继承的叙述哪些是正确的()a.在java中只允许单一继承b.在java中一个类只能实现一个接口c.在java中一个类不能同时继承一个类和实现一个接口d.java的单一继承使代码更可靠23.指出下面关于垃圾收集的哪些叙述哪些是正确的()a.程序开发者必须自己创建一个线程进行内存释放的工作b.垃圾收集将检查并释放不再使用的内存c.垃圾收集允许程序开发者明确指定并立即释放该内存d.垃圾收集能够在期望的时间释放被java对象使用的内存24.下面关于变量及其范围的叙述哪些是对的()a.实例变量是类的成员变量b.实例变量用关键字static声明c.在方法中定义的局部变量在该方法被执行时创建d.局部变量必须在使用前初始化25.根据下面给出的代码,确定