YAHOO笔试题

YAHOO笔试题

abstract class BaseClass
{
public virtual void MethodA()
{
Console.WriteLine("BaseClass");
}
public virtual void MethodB()
{
}
}
class Class1: BaseClass
{
public void MethodA()
{
Console.WriteLine("Class1");
}
public override void MethodB()
{
}
}
class Class2: Class1
{
new public void MethodB()
{
}
}
class MainClass
{
public static void Main(string[] args)
{
Class2 o = new Class2();
o.MethodA();
}
}

请问，此程序输出结果是:

1. BaseClass
2. BassClass Class1
3. Class1
4. Class1 BassClass

public static void Main(string[] args)
{
int i = 2000;
object o = i;
i = 2001;
int j =(int) o;
Console.WriteLine("i={0},o={1}, j={2}",i,o,j);
}

1. i=2001,o=2000,j=2000
2. i=2001,o=2001,,j=2001
3. i=2000,o=2001,,j=2000
4. i=2001,o=2000,j=2001

您要创建ASP.NET应用程序用于运行AllWin公司内部的Web站点，这个应用程序包含了50个页面。您想要配置这个应用程序以便当发生一个HTTP代码错误时它可以显示一个自定义的错误页面给用户。您想要花最小的代价完成这些目标，您应该怎么做？(多选)

1. 在这个应用程序的Global.asax文件中创建一个Application_Error过程去处理ASP.NET代码错误。
2. 在这个应用程序的Web.config文件中创建一个applicationError节去处理ASP.NET代码错误。
3. 在这个应用程序的Global.asax文件中创建一个CustomErrors事件去处理HTTP错误。
4. 在这个应用程序的Web.config文件中创建一个CustomErrors节去处理HTTP错误。

如下程序的运行结果是：

public abstract class A
{
public A()
{
Console.WriteLine('A');
}
public virtual void Fun()
{
Console.WriteLine("A.Fun()");
}
}

public class B: A
{
public B()
{
Console.WriteLine('B');
}

public new void Fun()
{
Console.WriteLine("B.Fun()");
}

public static void Main()
{
A a = new B();
a.Fun();
}
}

1. A B A.Fun()
2. A B B.Fun()
3. B A A.Fun()
4. B A B.Fun()

Which of these string definitions will prevent escaping on backslashes in C#?*

1. string s = #”n Test string”;
2. string s = “’n Test string”;
3. string s = @”n Test string”;
4. string s = “n Test string”;

Which of the following operations can you NOT perform on an ADO.NET DataSet?

1. A DataSet can be synchronised with a RecordSet.
2. A DataSet can be synchronised with the database.
3. A DataSet can be converted to XML.
4. You can infer the schema from a DataSet

In Object Oriented Programming, how would you describe encapsulation?

1. The conversion of one type of object to another.
2. The runtime resolution of method calls.
3. The exposition of data.
4. The separation of interface and implementation.

How does assembly versioning in .NET prevent DLL Hell?

1. The runtime checks to see that only one version of an assembly is on the machine at any one time.
2. .NET allows assemblies to specify the name AND the version of any assemblies they need to run.
3. The compiler offers compile time checking for backward compatibility.
4. It doesn’t.

三种常用的字符串判空串方法：

1: bool isEmpty = (str.Length == 0);
2: bool isEmpty = (str == String.Empty);
3: bool isEmpty = (str == "");

哪种方法最快？

1. 1
2. 2
3. 3

public sealed class SampleSingleton1
{
private int m_Counter = 0;
private SampleSingleton1()
{
Console.WriteLine(""初始化SampleSingleton1。"");
}

public static readonly SampleSingleton1 Singleton = new SampleSingleton1();

public void Counter()
{
m_Counter ++;
}
}

以上代码实现了设计模式中的哪种模式？

1. 原型
2. 抽象工厂
3. 单键
4. 生成器