XML Documentation Questions 1.Is XML case-sensitive? Ans. Yes.
2.What’s the difference between // comments, /* */ comments and /// comments? Ans. Single-line comments, multi-line comments, and XML documentation comments.
3.How do you generate documentation from the C# file commented properly with a command-line compiler? Ans. Compile it with the /doc switch.
Debugging and Testing Questions 1.What debugging tools come with the .NET SDK? Ans. 1. CorDBG – command-line debugger. To use CorDbg, you must compile the original C# file using the /debug switch.
2. DbgCLR – graphic debugger. Visual Studio .NET uses the DbgCLR.
2.What does assert() method do? Ans. In debug compilation, assert takes in a Boolean condition as a parameter, and shows the error dialog if the condition is false. The program proceeds without any interruption if the condition is true.
3.What’s the difference between the Debug class and Trace class? Ans. Documentation looks the same. Use Debug class for debug builds, use Trace class for both debug and release builds.
4.Why are there five tracing levels in System.Diagnostics.TraceSwitcher? Ans. The tracing dumps can be quite verbose. For applications that are constantly running you run the risk of overloading the machine and the hard drive. Five levels range from None to Verbose, allowing you to fine-tune the tracing activities.
5.Where is the output of TextWriterTraceListener redirected? Ans. To the Console or a text file depending on the parameter passed to the constructor.
6.How do you debug an ASP.NET Web application? Ans. Attach the aspnet_wp.exe process to the DbgClr debugger.
7.What are three test cases you should go through in unit testing? Ans. 1. Positive test cases (correct data, correct output). 2. Negative test cases (broken or missing data, proper handling). 3. Exception test cases (exceptions are thrown and caught properly).
8.Can you change the value of a variable while debugging a C# application? Ans. Yes. If you are debugging via Visual Studio.NET, just go to Immediate window.
ADO.NET and Database Questions 1. What is the role of the DataReader class in ADO.NET connections? Ans. It returns a read-only, forward-only rowset from the data source. A DataReader provides fast access when a forward-only sequential read is needed.
2.What are advantages and disadvantages of Microsoft provided data provider classes in ADO.NET? Ans. SQLServer.NET data provider is high-speed and robust, but requires SQL Server license purchased from Microsoft.
OLE-DB.NET is universal for accessing other sources, like Oracle, DB2, Microsoft Access and Informix. OLE-DB.NET is a .NET layer on top of the OLE layer, so it’s not as fastest and efficient as SqlServer.NET.
3.What is the wildcard character in SQL? Ans. Let’s say you want to query database with LIKE for all employees whose name starts with La. The wildcard character is %, the proper query with LIKE would involve ‘La%’.
4.Explain ACID rule of thumb for transactions. Ans. A transaction must be: 1.Atomic - it is one unit of work and does not dependent on previous and following transactions. 2.Consistent - data is either committed or roll back, no “in-between” case where something has been updated and something hasn’t. 3.Isolated - no transaction sees the intermediate results of the current transaction). 4.Durable - the values persist if the data had been committed even if the system crashes right after.
5.What connections does Microsoft SQL Server support? Ans. Windows Authentication (via Active Directory) and SQL Server authentication (via Microsoft SQL Server username and password).
6.Between Windows Authentication and SQL Server Authentication, which one is trusted and which one is untrusted? Ans. Windows Authentication is trusted because the username and password are checked with the Active Directory, the SQL Server authentication is untrusted, since SQL Server is the only verifier participating in the transaction.
7.What does the Initial Catalog parameter define in the connection string? Ans. The database name to connect to.
8.What does the Dispose method do with the connection object? Ans. Deletes it from the memory. To Do: answer better. The current answer is not entirely correct.
9.What is a pre-requisite for connection pooling? Ans. Multiple processes must agree that they will share the same connection, where every parameter is the same, including the security settings. The connection string must be identical.
Assembly Questions 1.How is the DLL Hell problem solved in .NET? Ans. Assembly versioning allows the application to specify not only the library it needs to run (which was available under Win32), but also the version of the assembly.
2.What are the ways to deploy an assembly? Ans. An MSI installer, a CAB archive, and XCOPY command.
3.What is a satellite assembly? Ans. When you write a multilingual or multi-cultural application in .NET, and want to distribute the core application separately from the localized modules, the localized assemblies that modify the core application are called satellite assemblies.
4.What namespaces are necessary to create a localized application? Ans.System.Globalization and System.Resources.
5.What is the smallest unit of execution in .NET? Ans. an Assembly.
6.When should you call the garbage collector in .NET? Ans. As a good rule, you should not call the garbage collector. However, you could call the garbage collector when you are done using a large object (or set of objects) to force the garbage collector to dispose of those very large objects from memory. However, this is usually not a good practice.
7.How do you convert a value-type to a reference-type? Ans. Use Boxing.
8.What happens in memory when you Box and Unbox a value-type? Ans. Boxing converts a value-type to a reference-type, thus storing the object on the heap. Unboxing converts a
reference-type to a value-type, thus storing the value on the stack.