Can you prevent your class from being inherited and becoming a base class for some other classes?

C# Interview Questions and Answers

(Continued from previous question...)

37. Can you prevent your class from being inherited and becoming a base class for some other classes?

Yes, that is what keyword sealed in the class definition is for. The developer trying to derive from your class will get a message: cannot inherit from Sealed class WhateverBaseClassName. It is the same concept as final class in Java.

(Continued on next question...)

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?
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• 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?
• What is boxing?
• 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?
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• How can you debug failed assembly binds?
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• How can you create a strong name for a .NET assembly?
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• Can you have two files with the same file name in GAC?
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• Is there an equivalent of exit() for quitting a C# .NET application?
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• 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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• What is the C# equivalent of C++ catch (…), which was a catch-all statement for any possible exception? Does C# support try-catch-finally blocks?
• 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?
• What connections does Microsoft SQL Server support?
• What is a satellite assembly?
• How is method overriding different from overloading?
• When do you absolutely have to declare a class as abstract (as opposed to free-willed educated choice or decision based on UML diagram)?
• 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?
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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?
• What optimizations does the C# compiler perform when you use the /optimize+ compiler option?
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• What is the top .NET class that everything is derived from?
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• Can you change the value of a variable while debugging a C# application?
• Are private class-level variables inherited?
• Can you inherit multiple interfaces?
• From a versioning perspective, what are the drawbacks of extending an interface as opposed to extending a class?
• Which one is trusted and which one is untrusted?
• What namespaces are necessary to create a localized application?
• Does Console.WriteLine() stop printing when it reaches a NULL character within a string?
• What is the advantage of using System.Text.StringBuilder over System.String?
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• Why do I get a security exception when I try to run my C# app?
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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++)?
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• 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?
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• Can multiple catch blocks be executed?
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• What is the role of the DataReader class in ADO.NET connections?
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• What is a multicast delegate?
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• What’s a multicast delegate?
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• What debugging tools come with the .NET SDK?
• What does assert() method do?
• What’s the difference between the Debug class and Trace class?
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• Explain constructor.
• Describe ways of cleaning up objects.
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• Which controls do not have events?
• What is the maximum size of the textbox?
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• Which control cannot be placed in MDI?
• What is the difference between proc. sent BY VAL and BY SUB?