1. class SuperClass {  2. public a geta() {  3. return new a();  4. }  5. }  6. class SubClass extends SuperClass {  7. public b geta() {  8. return new b();  9. }  10. }  Which is true?() A、 Compilation will succeed if a extends b.B、 Compilation will succeed if b extends a.C、 Compilation will always fail because of an error in line 7.D、 Compilation will always fail because of an error in line 8.

1. class SuperClass {  2. public a geta() {  3. return new a();  4. }  5. }  6. class SubClass extends SuperClass {  7. public b geta() {  8. return new b();  9. }  10. }  Which is true?() 

  • A、 Compilation will succeed if a extends b.
  • B、 Compilation will succeed if b extends a.
  • C、 Compilation will always fail because of an error in line 7.
  • D、 Compilation will always fail because of an error in line 8.

相关考题:

1. Everyone in our class ________ .A. like singingB. likes play footballC. like watch TVD. likes playing games

下面程序输出的结果为 #include"iostream.h" class A { public: A(){cout<<"CLASSA"<<endl;} ~A() {} }; class B:public A { public: B(){cout<<"CLASSB"<<endl;} ~B() {} }; void main() { A * p; p=new B; B *q; q=new B; }A.CLASS A CLASS BB.CLASS A CLASS B CLASS BC.CLASS A CLASS B CLASS A CLASS BD.CLASS A CLASS B CLASS B CLASS B

下面程序输出的结果为#include"iostream.h"class A{public:A( ){cout<<"CLASS A"<<endl;}~A( ){}};class B:public A{public:B( ){cout<<"CLASS B"<<endl;}~B( ){}};void main( ){A*p;p=new B;B *q;q=new B;}A.CLASS A CLASS BB.CLASS A CLASS B CLASS BC.CLASS A CLASS B CLASS A CLASS BD.CLASS A CLASS B CLASS B CLASS B

下面程序输出的结果为 #include"iostream.h” class A { public: A(){cout<<"CLASSA"<<endl;} ~A() {} }; class B:public A { public: B(){cout<<"CLASS B"<<endl;} ~B(){} }; void main() { A*p; p=new B;A.CLASS A CLASS B CLASS B CLASS BB.CLASS A CLASS B CLASS A CLASS BC.CLASS A CLASS B CLASS BD.CLASS A CLASS B

下面程序输出的结果为( )。 #inClUde”iostream.h” Class A {public: A(){cout<<“CLASS A”<<endl;} ~A()<)}; class B:public A {public: B(){cout<<”CLASSB”<<endl;} ~B(){}}; void main() {A*p; p=new B; B *q; q=new B;}A.CLASS A CLASS BB.CLASS A CLASS B CLASS BC.CLASS A ClASS BD.CLASS A CLASS B CLASS A CLASS B CLASS B CLASS B

1. public class Target {  2. private int i = 0;  3. public int addOne() {  4. return ++i;  5. }  6. }  And:  1. public class Client {  2. public static void main(String[] args) {  3. System.out.println(new Target().addOne());  4. }  5. }  Which change can you make to Target without affecting Client?() A、 Line 4 of class Target can be changed to return i++;B、 Line 2 of class Target can be changed to private int i = 1;C、 Line 3 of class Target can be changed to private int addOne() {D、 Line 2 of class Target can be changed to private Integer i = 0;

1. public interface A {  2. public void doSomething(String thing);  3. }  1. public class AImpl implements A {  2. public void doSomething(String msg) { }  3. }  1. public class B {  2. public A doit() {  3. // more code here  4. }  5.  6. public String execute() { 7. // more code here  8. }  9. }  1. public class C extends B {  2. public AImpl doit() {  3. // more code here  4. }  5.  6. public Object execute() {  7. // more code here  8. }  9. }  Which statement is true about the classes and interfaces in the exhibit?() A、 Compilation will succeed for all classes and interfaces.B、 Compilation of class C will fail because of an error in line 2.C、 Compilation of class C will fail because of an error in line 6.D、 Compilation of class AImpl will fail because of an error in line 2.

Class TestException  1. public class TestException extends Exception {  2. } Class a:  1. public class a {  2.  3. public String sayHello(String name) throws TestException {  4.  5. if(name == null) {  6. throw new TestException();  7. }  8.  9. return “Hello “+ name;  10. }  11.  12. }  A programmer wants to use this code in an application: 45. A a=new A();  46. System.out.println(a.sayHello(”John”));  Which two are true?()A、 Class a will not compile.B、 Line 46 can throw the unchecked exception TestException.C、 Line 45 can throw the unchecked exception TestException.D、 Line 46 will compile if the enclosing method throws a TestException.E、 Line 46 will compile if enclosed in a try block, where TestException is caught.

1. public class a {  2. public void method1() {  3. try {  4. B b=new b();  5. b.method2();  6. // more code here  7. } catch (TestException te) {  8. throw new RuntimeException(te);  9. }  10. }  11. }  1. public class b {  2. public void method2() throws TestException {  3. // more code here  4. }  5. }  1. public class TestException extends Exception {  2. }  Given:  31. public void method() {  32. A a=new a();  33. a.method1();  34. }  Which is true if a TestException is thrown on line 3 of class b?()A、 Line 33 must be called within a try block.B、 The exception thrown by method1 in class a is not required to be caught.C、 The method declared on line 31 must be declared to throw a RuntimeException.D、 On line 5 of class a, the call to method2 of class b does not need to be placed in a try/catch block.

1. public class A {  2. void A() {  3. System.out.println(“Class A”);  4. }  5. public static void main(String[] args) {  6. new A();  7. }  8. }  What is the result?()  A、 Class AB、 Compilation fails.C、 An exception is thrown at line 2.D、 An exception is thrown at line 6.E、 The code executes with no output.

在MCDU电子状态页报告里能查看故障()A、Class1Class3B、Class2Class3C、Class1Class2D、Class1,Class2Class3

1. public class Exception Test {  2. class TestException extends Exception {}  3. public void runTest() throws TestException {}  4. public void test() /* Point X */ {  5. runTest();  6. }  7. }  At Point X on line 4, which code is necessary to make the code compile?()  A、 No code is necessary.B、 throws ExceptionC、 catch ( Exception e )D、 throws RuntimeExceptionE、 catch ( TestException e)

现自:  1.  interface Color {  }      2. interface Weight  {  }      3.  //insert code here    和以下足六个声明:  class Boat extends Color, extends Weight  {  }     class Boat extends Color and Weight  {  }      class Boat extends Color, Weight  {  }  class Boat implements Color,  implements Weight  {  }     class Boat implements Color and Weight  {  }      class Boat implements Color, Weight  {  }    分别插入到第3行,有多少行可以编译? () A、  0B、  1C、  2D、  3

1. public class returnIt (  2. returnType methodA(byte x, double y) (  3. return (short) x/y * 2;  4. )  5. )   What is the valid returnType for methodA in line 2?()  A、 IntB、 ByteC、 LongD、 ShortE、 FloatF、 Double

1. public class enclosingone (  2. public class insideone{}  3. )  4. public class inertest(  5. public static void main (string[]args)(  6. enclosingone eo= new enclosingone ();  7. //insert code here  8. )  9. )    Which statement at line 7 constructs an instance of the inner class?()  A、 InsideOnew ei= eo.new InsideOn();B、 Eo.InsideOne ei = eo.new InsideOne();C、 InsideOne ei = EnclosingOne.new InsideOne();D、 EnclosingOne.InsideOne ei = eo.new InsideOne();

You work as an application developer at Certkiller .com. Certkiller .com has instructed you to create a class named MetricFormula. This class will be used to compare MetricUnit and EnglishUnit objects.The MetricFormula is currently defined as follows (Line numbers are used for reference purposes only): 1. public class MetricFormula2. { 3. 4. } You need to ensure that the MetricFormula class can be used to compare the required objects. What should you do? ()A、 Add the following code on line 1: : IComparable {B、 Add the following code on line 1: : IComparer {C、 Add the following code on line 3: public int Compare (object x, object y) {// implementation code }D、 Add the following code on line 3: public int CompareTo (object obj) {// implementation code }

多选题现有2 个文件:  1. package x;  2. public class X {  3. public static void doX() { System.out.print("doX "); }  4. }  和:  1. class Find {  2. public static void main(String [] args) {  3. //insert code here  4. }  5. }  哪两行分别插入到类Find 的第3 行将编译并产生输出“doX”? ()AdoX();BX.doX();Cx.X.doX();Dx.X myX = new x.X(); myX.doX();

单选题1. public class enclosingone (  2. public class insideone{}  3. )  4. public class inertest(  5. public static void main (string[]args)(  6. enclosingone eo= new enclosingone ();  7. //insert code here  8. )  9. )    Which statement at line 7 constructs an instance of the inner class?()A InsideOnew ei= eo.new InsideOn();B Eo.InsideOne ei = eo.new InsideOne();C InsideOne ei = EnclosingOne.new InsideOne();D EnclosingOne.InsideOne ei = eo.new InsideOne();

单选题Given classes defined in two different files:  1. package util;  2. public class BitUtils {  3. public static void process(byte[]) { /* more code here */ }  4. }  1. package app;  2. public class SomeApp {  3. public static void main(String[] args) {  4. byte[] bytes = new byte[256];  5. // insert code here  6. }  7. }  What is required at line 5 in class SomeApp to use the process method of BitUtils?()A process(bytes);B BitUtils.process(bytes);C util.BitUtils.process(bytes);D SomeApp cannot use methods in BitUtils.E import util.BitUtils.*; process(bytes);

单选题Given classes defined in two different files:  1. package util;  2. public class BitUtils {  3. private static void process(byte[] b) { }  4. }  1. package app;  2. public class SomeApp {  3. public static void main(String[] args) {  4. byte[] bytes = new byte[256];  5. // insert code here  6. }  7. }  What is required at line 5 in class SomeApp to use the process method of BitUtils?()A process(bytes);B BitUtils.process(bytes);C app.BitUtils.process(bytes);D util.BitUtils.process(bytes);E import util.BitUtils. *; process(bytes);F SomeApp cannot use the process method in BitUtils.

单选题现有:  1. interface Animal {  2. void eat();  3. }  4.  5. // insert code here  6.  7. public class HouseCat extends Feline {  8. public void eat() { }  9. }   和五个声明:  abstract class Feline implements Animal { }  abstract class Feline implements Animal { void eat(); }  abstract class Feline implements Animal { public void eat(); }  abstract class Feline implements Animal { public void eat() { } }  abstract class Feline implements Animal { abstract public void eat(); }  分别插入到第5行,有几个可以通过编译?()A0B1C2D3

单选题1. public class a {  2. public void method1() {  3. try {  4. B b=new b();  5. b.method2();  6. // more code here  7. } catch (TestException te) {  8. throw new RuntimeException(te);  9. }  10. }  11. }  1. public class b {  2. public void method2() throws TestException {  3. // more code here  4. }  5. }  1. public class TestException extends Exception {  2. }  Given:  31. public void method() {  32. A a=new a();  33. a.method1();  34. }  Which is true if a TestException is thrown on line 3 of class b?()A Line 33 must be called within a try block.B The exception thrown by method1 in class a is not required to be caught.C The method declared on line 31 must be declared to throw a RuntimeException.D On line 5 of class a, the call to method2 of class b does not need to be placed in a try/catch block.

多选题1. public class OuterClass {  2. private double d1 = 1.0;  3. // insert code here  4. }  Which two are valid if inserted at line 3?()Astatic class InnerOne { public double methoda() { return d1; } }Bstatic class InnerOne { static double methoda() { return d1; } }Cprivate class InnerOne { public double methoda() { return d1; } }Dprotected class InnerOne { static double methoda() { return d1; } }Epublic abstract class InnerOne { public abstract double methoda(); }

多选题1. public class A {  2. public void method1() {  3. B b=new B();  4. b.method2();  5. // more code here  6. }  7. }  1. public class B {  2. public void method2() {  3.C c=new C();  4. c.method3();  5. // more code here  6. }  7. }  1. public class C {  2. public void method3() {  3. // more code here  4. }  5. }  Given:  25. try {  26. A a=new A();  27. a.method1();  28. } catch (Exception e) {  29. System.out.print(”an error occurred”);  30. }  Which two are true if a NullPointerException is thrown on line 3 of class C?()AThe application will crash.BThe code on line 29 will be executed.CThe code on line 5 of class A will execute.DThe code on line 5 of class B will execute.EThe exception will be propagated back to line 27.

单选题1. public class A {  2. void A() {  3. System.out.println(“Class A”);  4. }  5. public static void main(String[] args) {  6. new A();  7. }  8. }  What is the result?()A Class AB Compilation fails.C An exception is thrown at line 2.D An exception is thrown at line 6.E The code executes with no output.

单选题1. public class Exception Test {  2. class TestException extends Exception {}  3. public void runTest() throws TestException {}  4. public void test() /* Point X */ {  5. runTest();  6. }  7. }  At Point X on line 4, which code is necessary to make the code compile?()A No code is necessary.B throws ExceptionC catch ( Exception e )D throws RuntimeExceptionE catch ( TestException e)

单选题In a class of 160 seniors, the ratio of boys to girls is 3 to 5. In the junior class, the ratio of boys to girls is 3 to 2. When the two classes are combined, the ratio of boys to girls is 1 to 1. How many students are in the junior class?A400B360C200D180E160

单选题Given a class Repetition:  1. package utils;  2.  3. public class Repetition {  4. public static String twice(String s) { return s + s; }  5. }  and given another class Demo:  1. // insert code here 2.  3. public class Demo {  4. public static void main(String[] args) {  5. System.out.println(twice(”pizza”));  6. }  7. }  Which code should be inserted at line 1 of Demo.java to compile and run Demo to print“pizzapizza”?()A import utils.*;B static import utils.*;C import utils.Repetition.*;D static import utils.Repetition. *;E import utils.Repetition.twice();F import static utils.Repetition.twice;G static import utils.Repetition.twice;