An example of a ctype and directcast.

C# Interview Questions and Answers

(Continued from previous question...)

211. An example of a ctype and directcast.

In the preceding example, the run-time type of Q is Double. CType succeeds because Double can be converted to Integer, but DirectCast fails because the run-time type of Q is not already Integer

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Other Interview Questions

• What's C#
• Is it possible to inline assembly or IL in C# code?
• Is it possible to have different access modifiers on the get/set methods of a property?
• Is it possible to have a static indexer in C#? allowed in C#.
• If I return out of a try/finally in C#, does the code in the finally-clause run?
• I was trying to use an out int parameter in one of my functions. How should I declare the variable that I am passing to it?
• How does one compare strings in C#?
• How do you specify a custom attribute for the entire assembly (rather than for a class)?
• How do you mark a method obsolete?
• How do you implement thread synchronization (Object.Wait, Notify,and CriticalSection) in C#?
• How do you directly call a native function exported from a DLL?
• How do I simulate optional parameters to COM calls?
• The C# keyword .int. maps to which .NET type?
• Which of these string definitions will prevent escaping on backslashes in C#?
• Which of these statements correctly declares a two-dimensional array in C#?
• If a method is marked as protected internal who can access it?
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• What compiler switch creates an xml file from the xml comments in the files in an assembly?
• What is a satellite Assembly?
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• How does assembly versioning in .NET prevent DLL Hell?
• Which .Gang of Four. design pattern is shown below?
• In the NUnit test framework, which attribute must adorn a test class in order for it to be picked up by the NUnit GUI?
• Which of the following operations can you NOT perform on an ADO.NET DataSet?
• In Object Oriented Programming, how would you describe encapsulation?
• What do you know about .NET assemblies?
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• What’s a strong name?
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• How can you debug failed assembly binds?
• Where are shared assemblies stored?
• How can you create a strong name for a .NET assembly?
• Where’s global assembly cache located on the system?
• Can you have two files with the same file name in GAC?
• So let’s say I have an application that uses MyApp.dll assembly ...
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• Is there an equivalent of exit() for quitting a C# .NET application?
• Can you prevent your class from being inherited and becoming a base class for some other classes?
• If a base class has a bunch of overloaded constructors ...
• I was trying to use an "out int" parameter in one of my functions. How should I declare the variable that I am passing to it?
• How do I make a DLL in C#?
• How do I simulate optional parameters to COM calls?
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• Is there regular expression (regex) support available to C# developers?
• Is there a way to force garbage collection?
• Does C# support properties of array types?
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• What is a satellite assembly?
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• Why would you use untrusted verificaion?
• What is the implicit name of the parameter that gets passed into the class set method?
• How do I register my code for use by classic COM clients?
• How do I do implement a trace and assert?
• How do I create a multilanguage, multifile assembly?
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• What is the syntax for calling an overloaded constructor within a constructor (this() and constructorname() does not compile)?
• What does the keyword virtual mean in the method definition?
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• How do I declare inout arguments in C#?
• Is there a way of specifying which block or loop to break out of when working with nested loops?
• What is the difference between const and static read-only?
• What does the parameter Initial Catalog define inside Connection String?
• What is the difference between System.String and System.StringBuilder classes?
• What is the top .NET class that everything is derived from?
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• Are private class-level variables inherited?
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• Why do I get a security exception when I try to run my C# app?
• Is there any sample C# code for simple threading?
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• How do you inherit from a class in C#?
• How do I port "synchronized" functions from Visual J++ to C#?
• Can I define a type that is an alias of another type (like typedef in C++)?
• Is it possible to have different access modifiers on the get/set methods of a property?
• Is it possible to have a static indexer in C#?
• Does C# support #define for defining global constants?
• Does C# support templates?
• Does C# support parameterized properties?
• Does C# support C type macros?
• Can you store multiple data types in System.Array?
• Is it possible to inline assembly or IL in C# code?
• Can you declare the override method static while the original method is non-static?
• Does C# support multiple inheritance?
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• What is the wildcard character in SQL?
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• What is an interface class?
• What is a multicast delegate?
• How does one compare strings in C#?
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• Why do I get an error (CS1006) when trying to declare a method without specifying a return type?
• How do I convert a string to an int in C#?
• How do you directly call a native function exported from a DLL?
• What is the .NET datatype that allows the retrieval of data by a unique key?
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• Can you prevent your class from being inherited by another class?
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• What’s an abstract class?
• When do you absolutely have to declare a class as abstract?
• What is an interface class?
• Why can’t you specify the accessibility modifier for methods inside the interface?
• What happens if you inherit multiple interfaces and they have conflicting method names?
• What’s the difference between an interface and abstract class?
• What is the difference between a Struct and a Class?
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• If a base class has a number of overloaded constructors, and an inheriting class has a number of overloaded constructors; can you enforce a call from an inherited constructor to a specific base constructor?
• What’s a delegate?
• What’s a multicast delegate?
• How do you generate documentation from the C# file commented properly with a command-line compiler?
• What debugging tools come with the .NET SDK?
• What does assert() method do?
• What’s the difference between the Debug class and Trace class?
• Why are there five tracing levels in System.Diagnostics.TraceSwitcher?
• Where is the output of TextWriterTraceListener redirected?
• How do you debug an ASP.NET Web application?
• What are three test cases you should go through in unit testing?
• Can you change the value of a variable while debugging a C# application?
• What is the role of the DataReader class in ADO.NET connections?
• What are advantages and disadvantages of Microsoft-provided data provider classes in ADO.NET?
• What is the wildcard character in SQL?
• Explain ACID rule of thumb for transactions.
• What connections does Microsoft SQL Server support?
• Between Windows Authentication and SQL Server Authentication, which one is trusted and which one is untrusted?
• What does the Initial Catalog parameter define in the connection string?
• What does the Dispose method do with the connection object?
• What is a pre-requisite for connection pooling?
• How is the DLL Hell problem solved in .NET?
• What are the ways to deploy an assembly?
• What is a satellite assembly?
• What namespaces are necessary to create a localized application?
• What is the smallest unit of execution in .NET?
• When should you call the garbage collector in .NET?
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• What happens in memory when you Box and Unbox a value-type?
• Difference between directcast and ctype.
• An example of a ctype and directcast.
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• directcast(123.34,integer) - should it throw an error? Why or why not?
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• Explain manifest & metadata.
• Difference between imperative and interrogative code.
• Difference between value and reference type.
• What are the two kinds of properties.
• Explain constructor.
• Describe ways of cleaning up objects.
• How can you clean up objects holding resources from within the code?
• Which controls do not have events?
• What is the maximum size of the textbox?
• Which property of the textbox cannot be changed at runtime?
• Which control cannot be placed in MDI?
• What is the difference between proc. sent BY VAL and BY SUB?