Given the following code fragment： public void create（） { Vector myVect； myVect = new Vector（）； } Which of the following statements are true？（） A、 The declaration on line 2 does not allocate memory space for the variable myVect.B、 The declaration on line 2 allocates memory space for a reference to a Vector object.C、 The statement on line 2 creates an object of class Vector.D、 The statement on line 3 creates an object of class Vector.E、 The statement on line 3 allocates memory space for an object of class Vector.
Given the following code fragment： public void create（） { Vector myVect； myVect = new Vector（）； } Which of the following statements are true？（）
- A、 The declaration on line 2 does not allocate memory space for the variable myVect.
- B、 The declaration on line 2 allocates memory space for a reference to a Vector object.
- C、 The statement on line 2 creates an object of class Vector.
- D、 The statement on line 3 creates an object of class Vector.
- E、 The statement on line 3 allocates memory space for an object of class Vector.
相关考题：
给出下面的代码段，下面的哪些陈述为真? ( ) public void create() { Vector myVect; myVect=new Vector(); } Ⅰ：第2行的声明不会为变量myVect分配内存空间。 Ⅱ：第2行的声明分配一个到Vector对象的引用的内存空间。 Ⅲ：第2行语句创建一个Vector类对象。 Ⅳ：第3行语句创建一个Vector类对象。A．Ⅱ、Ⅲ、ⅣB．Ⅱ、Ⅲ、ⅣC．Ⅰ、ⅢD．Ⅰ、Ⅳ
Given:Which two changes, taken together, would guarantee the output: 1, 2, 3, 4, 5, ?() A.move the line 12 print statement into the foo() methodB.change line 7 to public synchronized void go() {C.change the variable declaration on line 2 to private volatile int x;D.wrap the code inside the foo() method with a synchronized( this ) blockE.wrap the for loop code inside the go() method with a synchronized block synchronized(this){ //for loop code here }
Which of the following is a disadvantage of using the EIGRP protocol?() A. It does not scale wellB. It converges slower than OSPFC. It is a proprietary protocolD. It is a distance vector protocol
Which of the following is a disadvantage of using the EIGRP protocol?（）A、It does not scale wellB、It converges slower than OSPFC、It is a proprietary protocolD、It is a distance vector protocol
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.
Which lines of code are valid declarations of a native method when occurring within the declaration of the following class？（） public class Qf575 { // insert declaration of a native method here } A、native public void setTemperature（int kelvin）；B、private native void setTemperature（int kelvin）；C、protected int native getTemperature（）；D、public abstract native void setTemperature（int kelvin）；E、native int setTemperature（int kelvin） {}
You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. You create a page that contains the following code fragment： You write the following code segment in the code-behind file for the page： void BindData（object sender， EventArgs e） { lstLanguages.DataSource = CultureInfo.GetCultures（CultureTypes.AllCultures）； lstLanguages.DataTextField = "EnglishName"； lstLanguages.DataBind（）； } You need to ensure that the lstLanguages ListBox control maintains the selection of the user during postback. Which line of code should you insert in the constructor of the page？（）A、this.Init += new EventHandler(BindData); B、this.PreRender += new EventHandler(BindData); C、lstLanguages.PreRender += new EventHandler(BindData); D、lstLanguages.SelectedIndexChanged += new EventHandler(BindData);
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？（）A、 The application will crash.B、 The code on line 29 will be executed.C、 The code on line 5 of class A will execute.D、 The code on line 5 of class B will execute.E、 The exception will be propagated back to line 27.
Given the following code： 1） public void modify（） { 2） int i， j， k； 3） i = 100； 4） while （ i 0 ） { 5） j = i * 2； 6） System.out.println （" The value of j is " + j ）； 7） k = k + 1； 8） i--； 9） } 10） } Which line might cause an error during compilation？（） A、 line 4B、 line 6C、 line 7D、 line 8
package foo； import java.util.Vector； private class MyVector extends Vector { int i = 1； public MyVector（） { i = 2； } } public class MyNewVector extends MyVector { public MyNewVector（） { i = 4； } public static void main（String args[]） { MyVector v = new MyNewVector（）； } } What is the result？（）A、 Compilation succeeds.B、 Compilation fails because of an error at line 5.C、 Compilation fails because of an error at line 6.D、 Compilation fails because of an error at line 14.E、 Compilation fails because of an error at line 17.
Given the following code， which code fragments， when inserted at the indicated location， will succeed in making the program display a button spanning the whole window area？（） import java.awt.*； public class Q1e65 { public static void main（String args[]） { Window win = new Frame（）； Button but = new Button（"button"）； // insert code fragment here win.setSize（200， 200）； win.setVisible（true）； } } A、win.setLayout（new BorderLayout（））； win.add（but）；B、win.setLayout（new GridLayout（1， 1））； win.add（but）；C、win.setLayout（new BorderLayout（））； win.add（but， BorderLayout.CENTER）；D、win.add（but）；E、win.setLayout（new FlowLayout（））； win.add（but）；
Given the following code： 1） class Parent { 2） private String name； 3） public Parent（）{} 4） } 5） public class Child extends Parent { 6） private String department； 7） public Child（） {} 8） public String getValue（）{ return name； } 9） public static void main（String arg[]） { 10） Parent p = new Parent（）； 11） } 12） } Which line will cause error？（） A、 line 3B、 line 6C、 line 7D、 line 8E、 line 10
Which code fragments will succeed in printing the last argument given on the command line to the standard output， and exit gracefully with no output if no arguments are given？（） CODE FRAGMENT a： public static void main（String args[]） { if （args.length != 0） System.out.println（args[args.length-1]）； } CODE FRAGMENT b： public static void main（String args[]） { try { System.out.println（args[args.length]）； } catch （ArrayIndexOutOfBoundsException e） {} } CODE FRAGMENT c： public static void main（String args[]） { int ix = args.length； String last = args[ix]； if （ix != 0） System.out.println（last）； } CODE FRAGMENT d： public static void main（String args[]） { int ix = args.length-1； if （ix 0） System.out.println（args[ix]）； } CODE FRAGMENT e： public static void main（String args[]） { try { System.out.println（args[args.length-1]）； }catch （NullPointerException e） {} } A、Code fragment a.B、Code fragment b.C、Code fragment c.D、Code fragment d.E、Code fragment e.
Given the following code, write a line of code that, when inserted at the indicated location, will make the overriding method in Extension invoke the overridden method in class Base on the current object. class Base { public void print（ ） { System.out.println("base"); } } class Extention extends Base { public void print（ ） { System.out.println("extension"); // insert line of implementation here } } public class Q294d { public static void main(String args[]) { Extention ext = new Extention（ ）; ext.print（ ）; } } Fill in a single line of implementation.（）
Which of the following statements about declaration are true？（） A、 Declaration of primitive types such as boolean， byte and so on does not allocate memory space for the variable.B、 Declaration of primitive types such as boolean， byte and so on allocates memory space for the variable.C、 Declaration of nonprimitive types such as String， Vector and so on does not allocate memory space for the object.D、 Declaration of nonprimitive types such as String， Vector ans so on allocates memory space for the object.
Consider the following class： class Test（int i） { void test（int i） { System.out.println（“I am an int.”）； } void test（String s） { System.out.println（“I am a string.”）； } public static void main（String args） { Test t=new Test（）； char ch=“y”； t.test（ch）； } } Which of the statements below is true？（）A、 Line 5 will not compile， because void methods cannot be overridden.B、 Line 12 will not compile， because there is no version of test（） that rakes a charargument.C、 The code will compile but will throw an exception at line 12.D、 The code will compile and produce the following output： I am an int.E、 The code will compile and produce the following output： I am a String.
public class TestFive { private int x； public void foo（） { int current = x； x = current + 1； } public void go（） { for（int i=0；i5；i++） { new Thread（） { public void run（） { foo（）； System.out.print（x + “， “）； } }.start（）； }}} Which two changes， taken together， would guarantee the output： 1， 2， 3， 4， 5， ？（）A、 Move the line 12 print statement into the foo（） method.B、 Change line 7 to public synchronized void go（） {.C、 Change the variable declaration on line 3 to private volatile int x；.D、 Wrap the code inside the foo（） method with a synchronized（ this ） block.E、 Wrap the for loop code inside the go（） method with a synchronized block synchronized（this） { // for loop code here }.
You create a Web page named TestPage.aspx and a user control named TestUserControl.ascx. TestPage.aspx uses TestUserControl.ascx as shown in the following line of code. On TestUserControl.ascx， you need to add a read-only member named CityName to return the value "New York". You also must add code to TestPage.aspx to read this value. Which two actions should you perform？（）A、Add the following line of code to the TestUserControl.ascx.cs code-behind file. public string CityName { get { return "New York"; } } B、Add the following line of code to the TestUserControl.ascx.cs code-behind file. protected readonly string CityName = "New York"; C、Add the following code segment to the TestPage.aspx.cs code-behind file. protected void Page_Load(object sender, EventArgs e) { string s = testControl.CityName; } D、Add the following code segment to the TestPage.aspx.cs code-behind file. protected void Page_Load(object sender, EventArgs e) { string s = testControl.Attributes["CityName"]; }
You use the following declaration to add a Web user control named TestUserControl.ascx to an ASP.NET page named TestPage.aspx. You add the following code to the code-behind file of TestPage.aspx. private void TestMethod（）{ ...}You define the following delegate. public delegate void MyEventHandler（）； You need to add an event of type MyEventHandler named MyEvent to TestUserControl.ascx and attach the page’s TestMethod method to the event. Which two actions should you perform？（）A、Add the following line of code to TestUserControl.ascx.cs. public event MyEventHandler MyEvent；B、Add the following line of code to TestUserControl.ascx.cs. public MyEventHandler MyEvent；C、Replace the TestUserControl.ascx reference in TestPage.aspx with the following declaration. uc:TestUserControl ID="testControl" runat="server" OnMyEvent="TestMethod"/D、Replace the TestUserControl.ascx reference in TestPage.aspx with the following declaration. uc:TestUserControl ID="testControl" runat="server" MyEvent="TestMethod"/
You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. You create a page that contains the following code fragment. | English | Chinese | Japan | Korean | - 92 - Test Information Co.， Ltd. All rights reserved. You write the following code segment in the code-behind file for the page. void BindData（object sender， EventArgs e） { lstLanguages.DataSource = CultureInfo.GetCultures（CultureTypes.AllCultures）； lstLanguages.DataTextField = "EnglishName"； lstLanguages.DataBind（）； } You need to ensure that the lstLanguages ListBox control maintains the selection of the user during postback. Which line of code should you insert in the constructor of the page？（）A、this.Init += new EventHandler(BindData); B、this.PreRender += new EventHandler(BindData); C、lstLanguages.PreRender += new EventHandler(BindData); D、lstLanguages.SelectedIndexChanged += new EventHandler(BindData);
多选题Which lines of code are valid declarations of a native method when occurring within the declaration of the following class？（） public class Qf575 { // insert declaration of a native method here }Anative public void setTemperature（int kelvin）；Bprivate native void setTemperature（int kelvin）；Cprotected int native getTemperature（）；Dpublic abstract native void setTemperature（int kelvin）；Enative int setTemperature（int kelvin） {}
多选题Which of the following statements about declaration are true？（）ADeclaration of primitive types such as boolean， byte and so on does not allocate memory space for the variable.BDeclaration of primitive types such as boolean， byte and so on allocates memory space for the variable.CDeclaration of nonprimitive types such as String， Vector and so on does not allocate memory space for the object.DDeclaration of nonprimitive types such as String， Vector ans so on allocates memory space for the object.
单选题Given the following code： 1） class Parent { 2） private String name； 3） public Parent（）{} 4） } 5） public class Child extends Parent { 6） private String department； 7） public Child（） {} 8） public String getValue（）{ return name； } 9） public static void main（String arg[]） { 10） Parent p = new Parent（）； 11） } 12） } Which line will cause error？（）A line 3B line 6C line 7D line 8E line 10
单选题Which code fragments will succeed in printing the last argument given on the command line to the standard output， and exit gracefully with no output if no arguments are given？（） CODE FRAGMENT a： public static void main（String args[]） { if （args.length != 0） System.out.println（args[args.length-1]）； } CODE FRAGMENT b： public static void main（String args[]） { try { System.out.println（args[args.length]）； } catch （ArrayIndexOutOfBoundsException e） {} } CODE FRAGMENT c： public static void main（String args[]） { int ix = args.length； String last = args[ix]； if （ix != 0） System.out.println（last）； } CODE FRAGMENT d： public static void main（String args[]） { int ix = args.length-1； if （ix 0） System.out.println（args[ix]）； } CODE FRAGMENT e： public static void main（String args[]） { try { System.out.println（args[args.length-1]）； }catch （NullPointerException e） {} }ACode fragment a.BCode fragment b.CCode fragment c.DCode fragment d.ECode fragment e.
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Given the following code fragment： public void create（） { Vector myVect； myVect = new Vector（）； } Which of the following statements are true？（）AThe declaration on line 2 does not allocate memory space for the variable myVect.BThe declaration on line 2 allocates memory space for a reference to a Vector object.CThe statement on line 2 creates an object of class Vector.DThe statement on line 3 creates an object of class Vector.EThe statement on line 3 allocates memory space for an object of class Vector.
单选题package foo； import java.util.Vector； private class MyVector extends Vector { int i = 1； public MyVector（） { i = 2； } } public class MyNewVector extends MyVector { public MyNewVector （） { i = 4； } public static void main （String args ） { MyVector v = new MyNewVector（）； } } The file MyNewVector.java is shown in the exhibit. What is the result？（）A Compilation will succeed.B Compilation will fail at line 5.C Compilation will fail at line 6.D Compilation will fail at line 14.E Compilation will fail at line 17.