单选题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)

题目
单选题
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

 Hello

B

 Hello World

C

 Compilation fails.

D

 Hello World 5

E

 The code runs with no output.

F

 An exception is thrown at runtime.


相似考题
更多“单选题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)”相关问题
  • 第1题:

    请阅读下面程序 public class ThreadTest{ public static void main(String args[]) ( Thread t1=new Thread(new Hello()); Thread t2=new Thread(new Hello()); t1.start(); t2.start(); } } class Hello implements Runnable { int i; public void run() { while(true) { System.out.prinfin("Hello"+i++); if(i=5) break; } } } 该程序创建线程使用的方法是

    A.继承Thread类

    B.实现Runnable接口

    C.t1.start()

    D.t2.start()


    正确答案:B
    解析:本题考查线程的创建。Java中,线程的创建有两种方法:
      (1)通过实现Runnable接口创建线程。Runnable接口中只定义了一个run()方法作为线程体。
      (2)通过继承Thread类创建线程。Thread类本身实现了Runnable接口。
      无论使用哪种方法来创建线程,新建的线程不会自动运行,必须调用线程的start()方法,才能运行该线程。
      本题程序中的Hello类实现了Runnable接口,即采用的是第一种方法创建线程。因此,本题的正确答案是选项B。

  • 第2题:

    publicclassClassA{publicintgetValue(){intvalue=0;booleansetting=true;Stringtitle=”Hello”;(value||(setting&&title==Hello”)){return1;}(value==1&title.equals(”Hello”)){return2;}}}And:ClassAa=newClassA();a.getValue();Whatistheresult?()

    A.1

    B.2

    C.Compilationfails.

    D.Thecoderunswithnooutput.

    E.Anexceptionisthrownatruntime.


    参考答案:C

  • 第3题:

    写出程序运行的结果

    Public class Base

    Public virtual string Hello() {return “Base”;}

    Public class Sub:Base

    Public override string Hello() {return “Sub”;}

    1. Base b = new Base(); b.Hello;

    2. Sub s = new Sub(); s.Hello;

    3. Base b = new Sub (); b.Hello;

    4. Sub s = new Base(); s.Hello;


    正确答案:
     

  • 第4题:

    public class Foo {  public void main( String[] args ) {  System.out.println( “Hello” + args[0] );  }  }   What is the result if this code is executed with the command line?()

    • A、 Hello
    • B、 Hello Foo
    • C、 Hello world
    • D、 Compilation fails.
    • E、 The code does not run.

    正确答案:E

  • 第5题:

    class A {  public A() {  System.out.println(“hello from a”);  }  }  class B extends A {  public B () {  System.out.println(“hello from b”);  super();  }  }  public class Test {  public static void main(String args[]) {  A a = new B();  }  }   What is the result when main is executed?()  

    • A、 Compilation fails.
    • B、 hello from a
    • C、 hello from b
    • D、 hello from b hello from a
    • E、 hello from a hello from b

    正确答案:A

  • 第6题:

     public class X {   public static void main (String[]args)   {   string s = new string (“Hello”);   modify(s);   System.out.printIn(s);   }   public static void modify (String s)  {   s += “world!”;      }   }      What is the result?()    

    • A、 The program runs and prints “Hello”
    • B、 An error causes compilation to fail.
    • C、 The program runs and prints “Hello world!”
    • D、 The program runs but aborts with an exception.

    正确答案:A

  • 第7题:

    public class X {   public static void main (Stringargs) {   string s = new string (“Hello”);   modify(s);   System.out.printIn(s);   }   public static void modify (String s) {   s += “world!”;   }   }   What is the result?() 

    • A、The program runs and prints “Hello”
    • B、An error causes compilation to fail.
    • C、The program runs and prints “Hello world!”
    • D、The program runs but aborts with an exception.

    正确答案:A

  • 第8题:

    public class ClassA {  public int getValue() {  int value=0;  boolean setting = true;  String title=”Hello”;  (value || (setting && title == “Hello”)) { return 1; }  (value == 1 & title.equals(”Hello”)) { return 2; }  }  } And:  ClassA a = new ClassA();  a.getValue();  What is the result?() 

    • A、 1
    • B、 2
    • C、 Compilation fails.
    • D、 The code runs with no output.
    • E、 An exception is thrown at runtime.

    正确答案:C

  • 第9题:

    单选题
    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

     Hello

    B

     Hello World

    C

     Compilation fails.

    D

     Hello World 5

    E

     The code runs with no output.

    F

     An exception is thrown at runtime.


    正确答案: C
    解析: 暂无解析

  • 第10题:

    单选题
    public class X {   public static void main (String[]args)   {   string s = new string (“Hello”);   modify(s);   System.out.printIn(s);   }   public static void modify (String s)  {   s += “world!”;      }   }      What is the result?()
    A

     The program runs and prints “Hello”

    B

     An error causes compilation to fail.

    C

     The program runs and prints “Hello world!”

    D

     The program runs but aborts with an exception.


    正确答案: B
    解析: 暂无解析

  • 第11题:

    单选题
    11. public enum Title {  12. MR(”Mr.”), MRS(”Mrs.”), MS(”Ms.”);  13. private final String title;  14. private Title(String t) { title = t; }  15. public String format(String last, String first) {  16. return title + “ “ + first + “ “ + last;  17. }  18. }  19. public static void main(String[] args) {  20. System.out.println(Title.MR.format(”Doe”, “John”));  21. }  What is the result?()
    A

     Mr. John Doe

    B

     An exception is thrown at runtime.

    C

     Compilation fails because of an error in line 12.

    D

     Compilation fails because of an error in line 15.

    E

     Compilation fails because of an error in line 20.


    正确答案: C
    解析: 暂无解析

  • 第12题:

    单选题
    public class ClassA{ public int getValue(){ int value=0; boolean setting=true; String title="Hello"; if(value||(setting && title=="Hello")){return 1;} if(value==1&title.equals("Hello")){return 2;} } } And: ClassA a=new ClassA(); a.getValue(); What is the result?()
    A

    1

    B

    2

    C

    Compilation fails.

    D

    The code runs with no output.

    E

    An exception is thrown at runtime.


    正确答案: D
    解析: 暂无解析

  • 第13题:

    请阅读下面程序 public class ThreadTest { public static void main(String args[]) throws Exception{ int i=0; Hello t=new Hello(); while(true) { System.out.println("Good Moming"+i++); if (i==2 && t.isAlive()) { System. out.println("Main waiting for Hello!"); t.join(); //等待t运行结束 } if(i==5) break;} } } class Hello extends Thread { int i; public void run() { while(true){ System.out.println("Hello"+i++); if (i==5) break;}}} 为使该程序正确执行,下划线处的语句应是

    A.t.sleep()

    B.t.yield()

    C.t.interrupt()

    D.t.start()


    正确答案:D
    解析:本题考查线程的基本知识。程序中通过继承Thread类来创建线程,而Java中新创建的线程不会自动运行,必须调用线程的start()方法,才能运行该线程。因此,下划线处的语句应调用线程的start()方法,即t.start()。
      Thread类还提供了—些方法对线程进行基本控制,其中,join()方法使当前线程暂停执行,等待调用该方法的线程结束后,再恢复执行:isAlive()方法用来测试线程是否活着。
      因此,本题的正确答案是选项D。

  • 第14题:

    10.publicclassHello{11.Stringtitle;12.intvalue;13.publicHello(){14.title+=World”;15.}16.publicHello(intvalue){17.this.value=value;18.title=Hello”;19.Hello();20.}21.}and:30.Helloc=newHello(5);31.System.out.println(c.title);Whatistheresult?()

    A.Hello

    B.HelloWorld

    C.Compilationfails.

    D.HelloWorld5

    E.Thecoderunswithnooutput.

    F.Anexceptionisthrownatruntime.


    参考答案:C

  • 第15题:

    下列代码包括一个Html文件和一个Applet类。在hello. html文件的横线处填入相应内容,把HelloApplet嵌入在hello. html中。

    hello. html文件内容:

    <HTML>

    <HEAD>

    <TITLE>Hello</TITLE>

    </HEAD>

    <BODY>

    <APPLET CODE="【 】"WIDTH=150 HEIGHT=25>

    </APPLET>

    </BODY>

    </HTML>

    HelloApplet. java文件内容:

    import java. awt. *;

    import java. applet. *;

    public class HelloApplet extends Applet{

    public void paint(Graphics g){

    g. drawString("Hello!" ,25,25);

    }

    }


    正确答案:HelloApplet. class
    HelloApplet. class 解析:CODE属性给出包含applet的类文件名,并且必须包括扩展名“. class”。

  • 第16题:

    11. public enum Title {  12. MR(”Mr.”), MRS(”Mrs.”), MS(”Ms.”);  13. private final String title;  14. private Title(String t) { title = t; }  15. public String format(String last, String first) {  16. return title + “ “ + first + “ “ + last;  17. }  18. }  19. public static void main(String[] args) {  20. System.out.println(Title.MR.format(”Doe”, “John”));  21. }  What is the result?() 

    • A、 Mr. John Doe
    • B、 An exception is thrown at runtime.
    • C、 Compilation fails because of an error in line 12.
    • D、 Compilation fails because of an error in line 15.
    • E、 Compilation fails because of an error in line 20.

    正确答案:A

  • 第17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 23?()


    正确答案:13423

  • 第18题:

    现有:     class Pencil  {  public void write (String content){     System.out.println ("Write"+content);     }     }  class RubberPencil extends Pencil{     public void erase (String content){     System.out.println ("Erase"+content);     }     }  执行下列代码的结果是哪项?()      Pencil pen=new RubberPencil();      pen.write ("Hello");      pen.erase ("Hello");    

    • A、 Write Hello        Erase Hello
    • B、 Erase Hello        Write Hello
    • C、编译错误
    • D、运行时抛出异常

    正确答案:C

  • 第19题:

    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、 Hello
    • B、 Hello World
    • C、 Compilation fails.
    • D、 Hello World 5
    • E、 The code runs with no output.
    • F、 An exception is thrown at runtime.

    正确答案:C

  • 第20题:

    单选题
    package test; class Target{ public String name="hello"; } What can directly access and change the value of the variable name?()
    A

    any class

    B

    only the Target class

    C

    any class in the test package

    D

    any class that extends Target


    正确答案: D
    解析: 暂无解析

  • 第21题:

    单选题
    public class X {   public static void main (Stringargs) {   string s = new string (“Hello”);   modify(s);   System.out.printIn(s);   }   public static void modify (String s) {   s += “world!”;   }   }   What is the result?()
    A

    The program runs and prints “Hello”

    B

    An error causes compilation to fail.

    C

    The program runs and prints “Hello world!”

    D

    The program runs but aborts with an exception.


    正确答案: D
    解析: 暂无解析

  • 第22题:

    单选题
    public class Foo {  public void main( String[] args ) {  System.out.println( “Hello” + args[0] );  }  }   What is the result if this code is executed with the command line?()
    A

     Hello

    B

     Hello Foo

    C

     Hello world

    D

     Compilation fails.

    E

     The code does not run.


    正确答案: E
    解析: 暂无解析

  • 第23题:

    单选题
    class A {  public A() {  System.out.println(“hello from a”);  }  }  class B extends A {  public B () {  System.out.println(“hello from b”);  super();  }  }  public class Test {  public static void main(String args[]) {  A a = new B();  }  }   What is the result when main is executed?()
    A

     Compilation fails.

    B

     hello from a

    C

     hello from b

    D

     hello from b hello from a

    E

     hello from a hello from b


    正确答案: D
    解析: Call to super must be first statement in constructor. 

  • 第24题:

    单选题
    public class ClassA {  public int getValue() {  int value=0;  boolean setting = true;  String title=”Hello”;  (value || (setting && title == “Hello”)) { return 1; }  (value == 1 & title.equals(”Hello”)) { return 2; }  }  } And:  ClassA a = new ClassA();  a.getValue();  What is the result?()
    A

     1

    B

     2

    C

     Compilation fails.

    D

     The code runs with no output.

    E

     An exception is thrown at runtime.


    正确答案: D
    解析: 暂无解析