C# (Sharp) Programming Language Interview Questions & Answers

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System.Int32

BY VAL: changes will not be reflected back to the variable.
By REF: changes will be reflected back to that variable.( same as & symbol in c, c++)

The controls that do not have events.

Locked Porperty.

65536.

Timer control.

Call the dispose method from code for clean up of objects

Answer1
There is a perfect tool provide by .net frameworks calles Garbage collector, where by mean of GC we can clean up the object and reclaim the memory.The namespace used is System.GC

Answer2
the run time will maintain a service called as garbage collector.this service will take care of deallocating memory corresponding to objects.it works as a thread with least priority.when application demenads for memory the runtime will take care of setting the high priority for the garbage collector,so that it will be called for execution and memory will be released.the programmer can make a call to garbage colector by using GC class in ststem name space.

Constructor is a method in the class which has the same name as the class (in VB.Net its New()). It initialises the member attributes whenever an instance of the class is created.

Two types of properties in .Net: Get and Set

what are value types and reference types?
Value type - bool, byte, chat, decimal, double, enum , float, int, long, sbyte, short, strut, uint, ulong, ushort
Value types are stored in the Stack
Reference type - class, delegate, interface, object, string
Reference types are stored in the Heap

There are imperative and interrogative functions. Imperative functions are the one which return a value while the interrogative functions do not return a value.

Answer1
Manifest is metadata about assemblies. Metadata is machine-readable information about a resource, or “”data about data.” In .NET, metadata includes type definitions, version information, external assembly references, and other standardized information.

Answer2
Manifest: Manifest describes assembly itself. Assembly Name, version number, culture, strong name, list of all files, Type references, and referenced assemblies.
Metadata: Metadata describes contents in an assembly classes, interfaces, enums, structs, etc., and their containing namespaces, the name of each type, its visibility/scope, its base class, the nterfaces it implemented, its methods and their scope, and each method’s parameters, type’s properties, and so on.

Answer1
A Sub does not return anything whereas a Function returns something.

Answer2
-A Sub Procedure is a method will not return a value
-A sub procedure will be defined with a “Sub” keyword

Sub ShowName(ByVal myName As String)
Console.WriteLine(”My name is: ” & myName)
End Sub

-A function is a method that will return value(s).
-A function will be defined with a “Function” keyword

Function FindSum(ByVal num1 As Integer, ByVal num2 As Integer) As Integer
Dim sum As Integer = num1 + num2
Return sum
End Function

It would throw an InvalidCast exception as the runtime type of 123.34 (double) doesnt match with Integer.

Answer1
It would work fine. As the runtime type of 123.34 would be double, and Double can be converted to Integer.

Answer2
the ctype(123.34,integer) will work fine no errors

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

Anser1
DirectCast requires the run-time type of an object variable to bethe same as the specified type.The run-time performance ofDirectCast is better than that of CType, if the specified type and the run-time typeof the expression are the same. Ctype works fine if there is a valid conversion defined between the expression and the type.

Answer2
The difference between the two keywords is that CType succeeds as long as there is a valid conversion defined between the expression and the type, whereas DirectCast requires the run-time type of an object variable to be the same as the specified type. If the specified type and the run-time type of the expression are the same, however, the run-time performance of DirectCast is better than that of CType.

Use Boxing.

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.

an Assembly.

An MSI installer, a CAB archive, and XCOPY command.

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.

Deletes it from the memory.

The database name to connect to.