多选题10. interface Foo {  11. int bar();  12. }  13.  14. public class Beta {  15.  16. class A implements Foo {  17. public int bar() { return 1; }  18. }  19.  20. public int fubar( Foo foo) { return foo.bar(); }  21.  22. public void testFoo() {  23.  24. class A implements Foo {  25. public int bar() { return 2; }  26. }  27.  28. System.out.println( fubar( new A())); 29. }  30.  31. public static void main( String[] argv) {  32. new Beta().testFoo();  33. }  34. }  Which three statements are true?()ACompilation fails.BThe code compiles and the output is 2.CIf lines 16, 17 and 18 were removed, compilation would fail.DIf lines 24, 25 and 26 were removed, compilation would fail.EIf lines 16, 17 and 18 were removed, the code would compile and the output would be 2.FIf lines 24, 25 and 26 were removed, the code would compile and the output would be 1.

多选题
10. interface Foo {  11. int bar();  12. }  13.  14. public class Beta {  15.  16. class A implements Foo {  17. public int bar() { return 1; }  18. }  19.  20. public int fubar( Foo foo) { return foo.bar(); }  21.  22. public void testFoo() {  23.  24. class A implements Foo {  25. public int bar() { return 2; }  26. }  27.  28. System.out.println( fubar( new A())); 29. }  30.  31. public static void main( String[] argv) {  32. new Beta().testFoo();  33. }  34. }  Which three statements are true?()
A

Compilation fails.

B

The code compiles and the output is 2.

C

If lines 16, 17 and 18 were removed, compilation would fail.

D

If lines 24, 25 and 26 were removed, compilation would fail.

E

If lines 16, 17 and 18 were removed, the code would compile and the output would be 2.

F

If lines 24, 25 and 26 were removed, the code would compile and the output would be 1.


参考解析

解析: 暂无解析

相关考题:

Given:Which code, inserted at line 15, allows the class Sprite to compile?() A.Foo { public int bar() { return 1; }B.new Foo { public int bar() { return 1; }C.new Foo() { public int bar() { return 1; }D.new class Foo { public int bar() { return 1; }

10. public class ClassA {  11. public void count(int i) {  12. count(++i);  13. }  14. }  And:  20. ClassA a = new ClassA();  21. a.count(3);  Which exception or error should be thrown by the virtual machine?() A、 StackOverflowErrorB、 NullPointerExceptionC、 NumberFormatExceptionD、 IllegalArgumentExceptionE、 ExceptionlnlnitializerError

11. public void addStrings(List list) {  12. list.add(”foo”);  13. list.add(”bar”);  14. }  What must you change in this method to compile without warnings?() A、 add this code after line 11: list = (List) list;B、 change lines 12 and 13 to: list.add(”foo”); list.add(”bar”);C、 change the method signature on line 11 to: public void addStrings(List extends String list) {D、 change the method signature on line 11 to: public void addStrings(List super String list) {E、 No changes are necessary. This method compiles without warnings.

11. public class Test {  12. public void foo() {  13. assert false;  14. assert false;  15. }  16. public void bar(){  17. while(true){  18. assert false;  19. }  20. assert false;  21. }  22. }  What causes compilation to fail?()  A、 Line 13B、 Line 14C、 Line 18D、 Line 20

11. public interface Status {  12. /* insert code here */ int MY_VALUE = 10;  13. }  Which three are valid on line 12?()A、 finalB、 staticC、 nativeD、 publicE、 privateF、 abstractG、 protected

10. public class Hello {  11. String title;  12. int value;  13. public Hello() {  14. title += “ World”;  15. }  16. public Hello(int value) {  17. this.value = value;  18. title = “Hello”;  19. Hello();  20. }  21. }  and:  30. Hello c = new Hello(5);  31. System.out.println(c.title);  What is the result?() A、 HelloB、 Hello WorldC、 Compilation fails.D、 Hello World 5E、 The code runs with no output.F、 An exception is thrown at runtime.

10. interface Foo {}  11. class Alpha implements Foo {}  12. class Beta extends Alpha {}  13. class Delta extends Beta {  14. public static void main( String[] args) {  15. Beta x = new Beta();  16. // insert code here  17. }  18. }  Which code, inserted at line 16, will cause a java.lang.ClassCastException?() A、 Alpha a = x;B、 Foo f= (Delta)x;C、 Foo f= (Alpha)x;D、 Beta b = (Beta)(Alpha)x;

public class Foo {  public int a;  public Foo() { a = 3; }  public void addFive() { a += 5; }  }  and:  public class Bar extends Foo { public int a;  public Bar() { a = 8; }  public void addFive() { this.a +=5; }  }  invoked with:  Foo foo = new Bar();  foo.addFive();  System.out.println(”Value: “+ foo.a);  What is the result?() A、 Value: 3B、 Value: 8C、 Value: 13D、 Compilation fails.E、 The code runs with no output.F、 An exception is thrown at runtime.

10. class Line {  11. public class Point { public int x,y; }  12. public Point getPoint() { return new Point(); }  13. }  14. class Triangle {  15. public Triangle() {  16. // insert code here  17. }  18. }  Which code, inserted at line 16, correctly retrieves a local instance of a Point object?() A、 Point p = Line.getPoint();B、 Line.Point p = Line.getPoint();C、 Point p = (new Line()).getPoint();D、 Line.Point p = (new Line()).getPoint();

Given:   10. class One {   11. void foo() { }   12. }   13. class Two extends One {   14. //insert method here   15. }   Which three methods, inserted individually at line 14, will correctly complete class Two?()A、 public void foo() { /* more code here */ }B、 private void foo() { /* more code here */ }C、 protected void foo() { /* more code here */ }D、 int foo() { /* more code here */ }  E、 void foo() { /* more code here */ }

单选题public class Foo {  public int a;  public Foo() { a = 3; }  public void addFive() { a += 5; }  }  and:  public class Bar extends Foo { public int a;  public Bar() { a = 8; }  public void addFive() { this.a +=5; }  }  invoked with:  Foo foo = new Bar();  foo.addFive();  System.out.println(”Value: “+ foo.a);  What is the result?()A Value: 3B Value: 8C Value: 13D Compilation fails.E The code runs with no output.F An exception is thrown at runtime.

多选题Given:   10. class One {   11. void foo() { }   12. }   13. class Two extends One {   14. //insert method here   15. }   Which three methods, inserted individually at line 14, will correctly complete class Two?()Apublic void foo() { /* more code here */ }Bprivate void foo() { /* more code here */ }Cprotected void foo() { /* more code here */ }Dint foo() { /* more code here */ }Evoid foo() { /* more code here */ }

多选题10. interface Foo {  11. int bar();  12. }  13.  14. public class Beta {  15.  16. class A implements Foo {  17. public int bar() { return 1; }  18. }  19.  20. public int fubar( Foo foo) { return foo.bar(); }  21.  22. public void testFoo() {  23.  24. class A implements Foo {  25. public int bar() { return 2; }  26. }  27.  28. System.out.println( fubar( new A())); 29. }  30.  31. public static void main( String[] argv) {  32. new Beta().testFoo();  33. }  34. }  Which three statements are true?()ACompilation fails.BThe code compiles and the output is 2.CIf lines 16, 17 and 18 were removed, compilation would fail.DIf lines 24, 25 and 26 were removed, compilation would fail.EIf lines 16, 17 and 18 were removed, the code would compile and the output would be 2.FIf lines 24, 25 and 26 were removed, the code would compile and the output would be 1.

单选题11. public void addStrings(List list) {  12. list.add(”foo”);  13. list.add(”bar”);  14. }  What must you change in this method to compile without warnings?()A add this code after line 11: list = (List) list;B change lines 12 and 13 to: list.add(”foo”); list.add(”bar”);C change the method signature on line 11 to: public void addStrings(List extends String list) {D change the method signature on line 11 to: public void addStrings(List super String list) {E No changes are necessary. This method compiles without warnings.

单选题10. interface Foo { int bar(); }  11. public class Sprite {  12. public int fubar( Foo foo) { return foo.bar(); }  13. public void testFoo() {  14. fubar(  15. // insert code here  16.);  17. }  18. }  Which code, inserted at line 15, allows the class Sprite to compile?()A Foo { public int bar() { return 1; } }B new Foo { public int bar() { return 1; } }C newFoo() { public int bar(){return 1; } }D new class Foo { public int bar() { return 1; } }

单选题1. interface foo {  2. int k = 0;  3. } 4.    5. public class test implements Foo (  6. public static void main(String args[]) (  7. int i;  8. Test test = new test ();  9. i= test.k;  10.i= Test.k;  11.i= Foo.k;  12.)  13.)  14.        What is the result?()A Compilation succeeds.B An error at line 2 causes compilation to fail.C An error at line 9 causes compilation to fail.D An error at line 10 causes compilation to fail.E An error at line 11 causes compilation to fail.

单选题10. public class Foo implements java.io.Serializable {  11. private int x;  12. public int getX() { return x; }  12.publicFoo(int x){this.x=x; }  13. private void writeObject( ObjectOutputStream s)  14. throws IOException {  15. // insert code here  16. }  17. }  Which code fragment, inserted at line 15, will allow Foo objects to be correctly serialized and deserialized?()A s.writeInt(x);B s.serialize(x);C s.writeObject(x);D s.defaultWriteObject();

单选题1. import java.io.*;  2. public class Foo implements Serializable {  3. public int x, y;  4. public Foo( int x, int y) { this.x = x; this.y = y; }  5.  6. private void writeObject( ObjectOutputStream s)  7. throws IOException {  8. s.writeInt(x); s.writeInt(y)  9. }  10.  11. private void readObject( ObjectInputStream s)  12. throws IOException, ClassNotFoundException {  13.  14. // insert code here  15.  16. }  17. }  Which code, inserted at line 14, will allow this class to correctly serialize and deserialize?()A s.defaultReadObject();B this = s.defaultReadObject();C y = s.readInt(); x = s.readInt();D x = s.readInt(); y = s.readInt();

单选题10. class Line {  11. public class Point { public int x,y; }  12. public Point getPoint() { return new Point(); }  13. }  14. class Triangle {  15. public Triangle() {  16. // insert code here  17. }  18. }  Which code, inserted at line 16, correctly retrieves a local instance of a Point object?()A Point p = Line.getPoint();B Line.Point p = Line.getPoint();C Point p = (new Line()).getPoint();D Line.Point p = (new Line()).getPoint();

单选题10. interface Foo {}  11. class Alpha implements Foo {}  12. class Beta extends Alpha {}  13. class Delta extends Beta {  14. public static void main( String[] args) {  15. Beta x = new Beta();  16. // insert code here  17. }  18. }  Which code, inserted at line 16, will cause a java.lang.ClassCastException?()A Alpha a = x;B Foo f= (Delta)x;C Foo f= (Alpha)x;D Beta b = (Beta)(Alpha)x;

单选题1. class A {  2. public int getNumber(int a) {  3.     return a + 1;  4. }  5. }  6.    7. class B extends A {  8. public int getNumber (int a) {  9. return a + 2  10. }  11.    12. public static void main (String args[])  {  13. A a = new B();  14. System.out.printIn(a.getNumber(0));  15.    } 16. }     What is the result?()A Compilation succeeds and 1 is printed.B Compilation succeeds and 2 is printed.C An error at line 8 causes compilation to fail.D An error at line 13 causes compilation to fail.E An error at line 14 causes compilation to fail.

单选题10. public class ClassA {  11. public void count(int i) {  12. count(++i);  13. }  14. }  And:  20. ClassA a = new ClassA();  21. a.count(3);  Which exception or error should be thrown by the virtual machine?()A StackOverflowErrorB NullPointerExceptionC NumberFormatExceptionD IllegalArgumentExceptionE ExceptionlnlnitializerError

单选题Given:   11. public static void main(String[] args) {   12. Object obj = new int[] { 1, 2, 3 };   13. int[] someArray = (int[])obj;   14. for (int i : someArray) System.out.print(i + " ");   15. }   What is the result? ()A Compilation fails because of an error in line 13.B A ClassCastException is thrown at runtime.C 1 2 3D Compilation fails because of an error in line 14.E Compilation fails because of an error in line 12.

多选题1. class Super {  2. private int a;  3. protected Super(int a) { this.a = a; }  4. }  .....  11. class Sub extends Super {  12. public Sub(int a) { super(a); }  13. public Sub() { this.a= 5; }  14. }  Which two, independently, will allow Sub to compile?()AChange line 2 to: public int a;BChange line 2 to: protected int a;CChange line 13 to: public Sub() { this(5); }DChange line 13 to: public Sub() { super(5); }EChange line 13 to: public Sub() { super(a); }

单选题11. public class Test {  12. public void foo() {  13. assert false;  14. assert false;  15. }  16. public void bar(){  17. while(true){  18. assert false;  19. }  20. assert false;  21. }  22. }  What causes compilation to fail?()A Line 13B Line 14C Line 18D Line 20

填空题1. public class test {  2. public static string output = “”  3.    4. public static void foo(int i) {  5. try {  6. if(i= =1) {  7. throw new Exception ();  8. }  9. output += “1”;  10.}  11. catch(Exception e)  {  12. output += “2”;  13. return;  14.}  15. finally (  16. output += “3”;  17. )  18. output += “4”;  19. } 20.    21. public static void main (string args[])  (  22. foo(0);  23. foo(1);  24.    25. )  26. } What is the value of the variable output at line 24?()

多选题10. public class Bar {  11.static void foo(int...x) {  12. // insert code here  13. }  14. }  Which two code fragments, inserted independently at line 12, will allow the class to compile?()Aforeach(x) System.out.println(z);Bfor(int z : x) System.out.println(z);Cwhile( x.hasNext()) System.out.println( x.next());Dfor( int i=0; i x.length; i++ ) System.out.println(x[i]);

多选题11. public interface Status {  12. /* insert code here */ int MY_VALUE = 10;  13. }  Which three are valid on line 12?()AfinalBstaticCnativeDpublicEprivateFabstractGprotected