HOTSPOT

You are implementing a library method that accepts a character parameter and returns a string.

If the lookup succeeds, the method must return the corresponding string value. If the lookup fails, the method must return the value "invalid choice."

You need to implement the lookup algorithm.

How should you complete the relevant code? (To answer, select the correct keyword in each drop-down list in the answer area.)

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Correct Answer:

Explanation:

switch(letter)

{

case ‘a’:

case ‘m’:

default:

}

Reference: switch (C# Reference)

http://msdn.microsoft.com/en-us/library/06tc147t(v=vs.110).aspx

You use the Task.Run() method to launch a long-running data processing operation. The data processing operation often fails in times of heavy network congestion.

If the data processing operation fails, a second operation must clean up any results of the first operation.

You need to ensure that the second operation is invoked only if the data processing operation throws an unhandled exception.

What should you do?

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You are modifying an application that processes leases.

The following code defines the Lease class. (Line numbers are included for reference only.)

Leases are restricted to a maximum term of 5 years. The application must send a notification message if a lease request exceeds 5 years.

You need to implement the notification mechanism.

Which two actions should you perform? (Each correct answer presents part of the solution. Choose two.)

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You are developing an application that uses structured exception handling. The application includes a class named ExceptionLogger.

The ExceptionLogger class implements a method named LogException by using the following code segment:

public static void LogException(Exception ex)

You have the following requirements:

• Log all exceptions by using the LogException() method of the ExceptionLogger class.

• Rethrow the original exception, including the entire exception stack.

You need to meet the requirements.

Which code segment should you use?

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You are developing an application that includes a class named UserTracker.

The application includes the following code segment. (Line numbers are included for reference only.)

You need to add a user to the UserTracker instance.

What should you do?

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DRAG DROP

You develop an application that displays information from log files when errors occur. The application will prompt the user to create an error report that sends details about the error and the session to the administrator.

When a user opens a log file by using the application, the application throws an exception and closes.

The application must preserve the original stack trace information when an exception occurs during this process.

You need to implement the method that reads the log files.

How should you complete the relevant code? (To answer, drag the appropriate code segments to the correct locations in the answer area. Each code segment may be used once, more than once, or not at all. You may need to drag the split bar between panes or scroll to view content.)

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Correct Answer:

Explanation:

StreamReader – Implements a TextReader that reads characters from a byte stream in a particular encoding.

Reference: http://msdn.microsoft.com/en-us/library/system.io.streamreader(v=vs.110).aspx

Once an exception is thrown, part of the information it carries is the stack trace. The stack trace is a list of the method call hierarchy that starts with the method that throws the exception and ends with the method that catches the exception. If an exception is re-thrown by specifying the exception in the throw statement, the stack trace is restarted at the current method and the list of method calls between the original method that threw the exception and the current method is lost. To keep the original stack trace information with the exception, use the throw statement without specifying the exception.

Reference: http://msdn.microsoft.com/en-us/library/ms182363(v=vs.110).aspx

Incorrect:

StringReader – Implements a TextReader that reads from a string.

Reference: http://msdn.microsoft.com/en-us/library/system.io.stringreader(v=vs.110).aspx

DRAG DROP

You are developing an application that includes a class named Kiosk. The Kiosk class includes a static property named Catalog.

The Kiosk class is defined by the following code segment. (Line numbers are included for reference only.)

You have the following requirements:

• Initialize the _catalog field to a Catalog instance.

• Initialize the _catalog field only once.

• Ensure that the application code acquires a lock only when the _catalog object must be instantiated.

You need to meet the requirements.

Which three code segments should you insert in sequence at line 09? (To answer, move the appropriate code segments from the list of code segments to the answer area and arrange them in the correct order.)

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Correct Answer:

Explanation:

After taking a lock you must check once again the _catalog field to be sure that other threads didn’t instantiated it in the meantime.

DRAG DROP

You are developing an application that will include a method named GetData. The GetData() method will retrieve several lines of data from a web service by using a System.IO.StreamReader object.

You have the following requirements:

• The GetData() method must return a string value that contains the first line of the response from the web service.

• The application must remain responsive while the GetData() method runs.

You need to implement the GetData() method.

How should you complete the relevant code? (To answer, drag the appropriate objects to the correct locations in the answer area. Each object may be used once, more than once, or not at all. You may need to drag the split bar between panes or scroll to view content.)

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Correct Answer:

Explanation:

Box 1. async Box 2. await Box 3. ReadLineAsync();

Incorrect:

Not Box 3: ReadToEndAsync() is not correct since only the first line of the response is required.

You are adding a public method named UpdateScore to a public class named ScoreCard.

The code region that updates the score field must meet the following requirements:

• It must be accessed by only one thread at a time.

• It must not be vulnerable to a deadlock situation.

You need to implement the UpdateScore() method.

What should you do?

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DRAG DROP

You are developing an application that implements a set of custom exception types.

You declare the custom exception types by using the following code segments:

The application includes a function named DoWork that throws .NET Framework exceptions and custom exceptions.

The application contains only the following logging methods:

The application must meet the following requirements:

• When AdventureWorksValidationException exceptions are caught, log the information by using the static void Log (AdventureWorksValidationException ex) method.

• When AdventureWorksDbException or other AdventureWorksException exceptions are caught, log the information by using the static void I oq( AdventureWorksException ex) method.

You need to meet the requirements.

How should you complete the relevant code? (To answer, drag the appropriate code segments to the correct locations in the answer area. Each code segment may be used once, more than once, or not at all. You may need to drag the split bar between panes or scroll to view content.)

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Correct Answer:

Explanation:

Go from the most specific exception to the least on.

So the order would be: