单选题23. Object [] myObjects = {  24. new integer(12),  25. new String(”foo”),  26. new integer(5),  27. new Boolean(true)  28. };  29. Arrays.sort(myObjects);  30. for( int i=0; i31. System.out.print(myObjects[i].toString());  32. System.out.print(” “);  33. }  What is the result?()A Compilation fails due to an error in line 23.B Compilation fails due to an error in line 29.C A ClassCastException occurs in line 29.D A ClassCastException occurs in line 31.E The value of all four objects prints in natural order.

单选题
23. Object [] myObjects = {  24. new integer(12),  25. new String(”foo”),  26. new integer(5),  27. new Boolean(true)  28. };  29. Arrays.sort(myObjects);  30. for( int i=0; i31. System.out.print(myObjects[i].toString());  32. System.out.print(” “);  33. }  What is the result?()
A

 Compilation fails due to an error in line 23.

B

 Compilation fails due to an error in line 29.

C

 A ClassCastException occurs in line 29.

D

 A ClassCastException occurs in line 31.

E

 The value of all four objects prints in natural order.


参考解析

解析: 暂无解析

相关考题:

本题中,用表格表现某个月的月历,其中标题是从Sunday到Saturday,表格中的各项是可以修改的。 import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.table.*; public class java2 ( public static void main(String[]args) { try{ UIManager.setLookAndFeel(UIManager.getSys- temLookAndFeelClassName): } catch(Exception e) JFrame. frame=new CalendarTableFrame; frame.setDefaultCloseOperation(JFrame.EXIT_ oN CLOSE); frame.show; } } clasgCalendarTableFrame. extends JFrame { private static final int WIDTH=500; private static final int HEIGHT=150: private cells= { {null,null,null,new Integer(1),new Integer (2),new Integer(3),new Integer(4)), {new Integer(5),new Integer(6),new Integer (7).new Integer(8),new Integer(9),new Integer (10),new Integer(11)), {new Integer(12),new Integer(13),new Integer (14),new Integer(15),new Integer(16),new Integer (17),new Integer(18)), {new Integer(19),new Integer(20),new Integer (21),new Integer(22),new Integer(23),new Integer (24),new Integer(25)), {new Integer(26),new Integer(27),new Integer (28),new Integer(29),new Integer(30),new Integer (31),null} }; private String[]columnNames={ "Sunday","Monday","Tuesday","Wednesday", "Thursday","Friday","Saturday" }; public CalendarTableFrame{ setTitle("java2"); setSize(WIDTH,HEIGHT); JTable table=new ; getContentPane.add(new JScrollPane(table), BorderLayout.CENTER); } }

阅读以下说明和Java代码,将应填入(n)处的字句写在对应栏内【说明】编写字符界面的Application程序,接收依次输入的10个整型数据,每个数据一行,将这些数据按升序排序后从系统的标准输出设备输出。【Java代码】import java.iO.*;import java.util.* ;public class compositor{public static void main ( String args[] ){final int NUMBER=10;Vector dataVector=new Vector ();try{BufferedReader br=new BufferedReader ((1) InputStreamReader ( System.in ));System.out.println ("请输入"+NUMBER+"个整数");for (int i=0; i<NUMBER; i++ ){int temp=Integer.parselnt ( br.(2));int low=0, high=i-1, mid=0;while ((3)){System.out.println ( low+","+mid+","+high );(4);if ((( Integer ) dataVectOr.get( mid )) .intValue () ==temp ){data Vector.insertElementAt ( new Integer ( temp ), mid );break;}else if ((( Integer ) dataVector.get ( mid )) .intValue ( ) >temp ){high=mid-1;}else{(5);}}if ( low>high ){dataVector, insertElementAt ( new Integer ( temp ), iow );}}//输出System.out.println ( "\n升序的排序结果为; ");for (int i=0; i<NUMBER; i++ ){System.out.print ( dataVector.get( i ) .toString () +"\t" );}}catch ( NumberFormatException nfe){System.out.println ( nfe.toString ());System.out.println ( "整数格式输入错误。");}catch ( IOException ioe ){System.out.println ( ioe.toString ());}}}

public static void main(String[]args){Integer i=new Integer(1)+new Integer(2);switch(i){case3:System.out.println(three);break;default:System.out.println(other);break;}}Whatistheresult?()A.threeB.otherC.Anexceptionisthrownatruntime.D.Compilationfailsbecauseofanerroronline12.E.Compilationfailsbecauseofanerroronline13.F.Compilationfailsbecauseofanerroronline15.

23.Object[]myObjects={24.newinteger(12),25.newString(”foo”),26.newinteger(5),27.newBoolean(true)28.};29.Arrays.sort(myObjects);30.for(inti=0;i31.System.out.print(myObjects[i].toString());32.System.out.print(”);33.}Whatistheresult?()A.Compilationfailsduetoanerrorinline23.B.Compilationfailsduetoanerrorinline29.C.AClassCastExceptionoccursinline29.D.AClassCastExceptionoccursinline31.E.Thevalueofallfourobjectsprintsinnaturalorder.

以下程序的运行结果为?class ValHold{public int i = 10;}public class ObParm{public static void main(String argv[]){ObParm o = new ObParm();o.amethod();}public void amethod(){int i = 99;ValHold v = new ValHold();v.i=30;another(v,i);System.out.print( v.i );}public void another(ValHold v, int i){i=0;v.i = 20;ValHold vh = new ValHold();v = vh;System.out.print(v.i);System.out.print(i);}}A.10030B. 20030C. 209930D. 10020

public class Test {  public static void add3 (Integer i) {  int val = i.intValue();  val += 3;  i = new Integer(val); }  public static void main(String args[]) {  Integer i = new Integer(0);  add3(i);  System.out.println(i.intValue());  }  }   What is the result? () A、 0B、 3C、 Compilation fails.D、 An exception is thrown at runtime.

class Beta {  public static void main(String [] args) {  Integer x = new Integer(6) * 7;  if (x != 42) {  System.out.print("42 ");  } else if (x 〈 new Integer(44-1)) {  System.out.println("less");  } else {  System.out.print("done"); } } }  结果是什么?() A、lessB、42C、doneD、编译失败

public class Base {  public static final String FOO = “foo”;  public static void main(String[] args) {  Base b = new Base();  Sub s = new Sub();  System.out.print(Base.FOO);  System.out.print(Sub.FOO);  System.out.print(b.FOO);  System.out.print(s.FOO);  System.out.print(((Base)s).FOO);  } }  class Sub extends Base {public static final String FOO=bar;}  What is the result?() A、 foofoofoofoofooB、 foobarfoobarbarC、 foobarfoofoofooD、 foobarfoobarfooE、 barbarbarbarbarF、 foofoofoobarbarG、 foofoofoobarfoo

Given:  Integer i = new Integer (42);  Long l = new Long (42);  Double d = new Double (42.0);   Which two expression evaluate to true?()A、 (i = = l)B、 (i = = d)C、 (d = = l)D、 (i.equals(d))E、 (i.equals(i))F、 (i.equals(42))

23. Object [] myObjects = {  24. new integer(12),  25. new String(”foo”),  26. new integer(5),  27. new Boolean(true)  28. };  29. Arrays.sort(myObjects);  30. for( int i=0; i31. System.out.print(myObjects[i].toString());  32. System.out.print(” “);  33. }  What is the result?()  A、 Compilation fails due to an error in line 23.B、 Compilation fails due to an error in line 29.C、 A ClassCastException occurs in line 29.D、 A ClassCastException occurs in line 31.E、 The value of all four objects prints in natural order.

public static void main( String[] args ) {  Integer a = new Integer(10);  Integer b = new Integer(10);  Integer c = a;  int d = 10;  double e = 10.0;  }   Which three evaluate to true?()   A、 (a == c)B、 (d == e)C、 (b == d)D、 (a == b)E、 (b == c)F、 (d == 10.0)

Integer i = new Integer (42);  Long 1 = new Long (42);  Double d = new Double (42.0);   Which two expressions evaluate to True?()A、 (i ==1)B、 (i == d)C、 (d == 1)D、 (i.equals (d))E、 (d.equals (i))F、 (i.equals (42)

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 23?()

11. class Payload {  12. private int weight;  13. public Payload(int wt) { weight = wt; }  13. public void setWeight(mt w) { weight = w; }  15. public String toString { return Integer.toString(weight); }  16. }  17.  18. public class TestPayload {  19. static void changePayload(Payload p) { 20. /* insert code here */ 21. }  22.  23. public static void main(String[] args) {  24. Payload p = new Payload();  25. p.setWeight(1024);  26. changePayload(p);  27. System.out.println(”The value of p is “+ p);  28. }  29. }  Which statement, placed at line 20, causes the code to print “The value of p is 420.”?() A、 p.setWeight(420);B、 p.changePayload(420);C、 p = new Payload(420);D、 Payload.setWeight(420);E、 p = Payload.setWeight(420);F、 p = new Payload(); p.setWeight(420);

10. class Inner {  11. private int x;  12. public void setX( int x) { this.x = x; }  13. public int getX() { return x; }  14. }  15.  16. class Outer {  17. private Inner y;  18. public void setY( Inner y) { this.y = y; }  19. public Inner getY() { return y; }  20. }  21.  22. public class Gamma {  23. public static void main( String[] args) { 24. Outer o = new Outer(); 25. Inner i = new Inner();  26.int n=10;  27. i.setX(n);  28. o.setY(i);  29. // insert code here  30. System.out.println( o.getY().getX());  31. }  32. }  Which three code fragments, added individually at line 29, produce the output 100?()A、 n = 100;B、 i.setX( 100);C、 o.getY().setX( 100);D、 i = new Inner(); i.setX( 100);E、 o.setY( i); i = new Inner(); i.setX( 100);F、 i = new Inner(); i.setX( 100); o.setY( i);

public class test {   public static void add3 (Integer i){  int val = i.intValue ( );   val += 3;   i = new Integer (val);    }     public static void main (String args [ ] )  { Integer i = new Integer (0);    add3 (i);   system.out.printIn (i.intValue ( ) );   }    }   What is the result?()A、 Compilation will fail.B、 The program prints “0”.C、 The program prints “3”.D、 Compilation will succeed but an exception will be thrown at line 3.

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.

单选题import java.util.*;  class KeyMaster {  public int i;  public KeyMaster(int i) { this.i = i; }  public boolean equals(Object o) { return i == ((KeyMaster)o).i; }  public int hashCode() { return i; }  }  public class MapIt {  public static void main(String[] args) {  Set set = new HashSet();  KeyMaster k1 = new KeyMaster(1);  KeyMaster k2 = new KeyMaster(2);  set.add(k1); set.add(k1);  set.add(k2); set.add(k2);  System.out.print(set.size() + “:”);  k2.i = 1;  System.out.print(set.size() + “:”);  set.remove(k1);  System.out.print(set.size() + “:”);  set.remove(k2);  System.out.print(set.size()); }  }  What is the result?()A 4:4:2:2B 4:4:3:2C 2:2:1:0D 2:2:0:0E 2:1:0:0F 2:2:1:1G 4:3:2:1

多选题10. class Inner {  11. private int x;  12. public void setX( int x) { this.x = x; }  13. public int getX() { return x; }  14. }  15.  16. class Outer {  17. private Inner y;  18. public void setY( Inner y) { this.y = y; }  19. public Inner getY() { return y; }  20. }  21.  22. public class Gamma {  23. public static void main( String[] args) { 24. Outer o = new Outer(); 25. Inner i = new Inner();  26.int n=10;  27. i.setX(n);  28. o.setY(i);  29. // insert code here  30. System.out.println( o.getY().getX());  31. }  32. }  Which three code fragments, added individually at line 29, produce the output 100?()An = 100;Bi.setX( 100);Co.getY().setX( 100);Di = new Inner(); i.setX( 100);Eo.setY( i); i = new Inner(); i.setX( 100);Fi = new Inner(); i.setX( 100); o.setY( i);

单选题public static void main(String[]args){ Integer i=new Integer(1)+new Integer(2); switch(i){ case3:System.out.println("three");break; default:System.out.println("other");break; } } Whatistheresult?()AthreeBotherCAnexceptionisthrownatruntime.DCompilationfailsbecauseofanerroronline12.ECompilationfailsbecauseofanerroronline13.FCompilationfailsbecauseofanerroronline15.

多选题Given:  Integer i = new Integer (42);  Long l = new Long (42);  Double d = new Double (42.0);   Which two expression evaluate to true?()A(i = = l)B(i = = d)C(d = = l)D(i.equals(d))E(i.equals(i))F(i.equals(42))

单选题public class Test {  public static void add3 (Integer i) {  int val = i.intValue();  val += 3;  i = new Integer(val); }  public static void main(String args[]) {  Integer i = new Integer(0);  add3(i);  System.out.println(i.intValue());  }  }   What is the result? ()A 0B 3C Compilation fails.D An exception is thrown at runtime.

单选题public class test {  public static void add3 (Integer i)  int val = i.intValue ( );  val += 3;  i = new Integer (val);  } public static void main (String args [ ] )  {  Integer  i = new Integer (0);  add3 (i);  system.out.printIn (i.intValue ( )  );  } What is the result?()A Compilation will fail.B The program prints “0”.C The program prints “3”.D Compilation will succeed but an exception will be thrown at line 3.

单选题class Beta {  public static void main(String [] args) {  Integer x = new Integer(6) * 7;  if (x != 42) {  System.out.print("42 ");  } else if (x 〈 new Integer(44-1)) {  System.out.println("less");  } else {  System.out.print("done"); } } }  结果是什么?()AlessB42CdoneD编译失败

单选题11. class Payload {  12. private int weight;  13. public Payload(int wt) { weight = wt; }  13. public void setWeight(mt w) { weight = w; }  15. public String toString { return Integer.toString(weight); }  16. }  17.  18. public class TestPayload {  19. static void changePayload(Payload p) { 20. /* insert code here */ 21. }  22.  23. public static void main(String[] args) {  24. Payload p = new Payload();  25. p.setWeight(1024);  26. changePayload(p);  27. System.out.println(”The value of p is “+ p);  28. }  29. }  Which statement, placed at line 20, causes the code to print “The value of p is 420.”?()A p.setWeight(420);B p.changePayload(420);C p = new Payload(420);D Payload.setWeight(420);E p = Payload.setWeight(420);F p = new Payload(); p.setWeight(420);

单选题public class Base {  public static final String FOO = “foo”;  public static void main(String[] args) {  Base b = new Base();  Sub s = new Sub();  System.out.print(Base.FOO);  System.out.print(Sub.FOO);  System.out.print(b.FOO);  System.out.print(s.FOO);  System.out.print(((Base)s).FOO);  } }  class Sub extends Base {public static final String FOO=bar;}  What is the result?()A foofoofoofoofooB foobarfoobarbarC foobarfoofoofooD foobarfoobarfooE barbarbarbarbarF foofoofoobarbarG foofoofoobarfoo

多选题Integer i = new Integer (42);   Long 1 = new Long (42);  Double d = new Double (42.0); Which two expressions evaluate to True? ()A(i ==1)B(i == d)C(d == 1)D(i.equals (d))E(d.equals (i))F(i.equals (42))