C# Interview Questions

C is the correct answer. Interfaces dont have constructors so they cant be instantiated.

http://msdn.microsoft.com/en-US/library/vstudio/ms173156.aspx

C) Interfaces can be instantiated

If you write in Java then the application will run in a JRE on UNIX but you have to compile the application on Windows first. Then deploy it to UNIX.

You can use mono .net for this

The best way to do this would be doing the same in global.asax application_error method.

Thanks
Vijay

By using "if else" conditional statement

nice answer peter

The "==" operand on the 2 int's is comparing value types. Here the content is compared. After boxing the value types into objects, i.e. reference types, the "==" operand compares the references (memo...

Code
if(dataset.Tables.count!=0)
{
do some operation
}
else
{
nothing...
}

Thank you Seeker911, your answer helped me :)

all the three statements are true...

The correct answer is B: as constructors need not be public we can have private constructors also for instance a singleton object has a private constructor

Not necessarily. Actually GetHashCode() can always return the same value... :-) Say "1". And everything will work well. Just Hashtable with such a key will not be efficient. Keys in the hashtable are ...

FALSE

Both Equals() and GetHashCode() can be overridden by the developer for user-defined classes, so there is no guaranteed behavior.

People, please read the question before answering, don't just answer "Why" is the question - not "how".

String is an array of bytes.
When are you ave to change it, you have to create the new one; because the string is always considered as a constant.

Folks:

Empty cases allowed to fall through in C#.

Most of the other answers are right, but there is a caveat.

Empty cases are allowed to fall through. However, the last case statement always needs a break - empty or not.

It is not mandatory for a derived class to override the virtual base method. Nevertheless, derived class can opt to override the virtual base method to redefine the functionality.

The answer is A) TRUE. If you declare a virtual method in a class , its not mandatory to override it in the sub class. However, In case of abstract class, the answer would be B) False since if you ...

Keyword sealed can be used with class declaration to prevent it from being sub-classed.
Keyword sealed can be used in method declaration to prevent it from being overridden.

To restrict users from inheriting the class by sealing the class using "sealed" keyword i.e. no class can be drieved from a sealed class. both Class and Method can be sealed, in that case Method cannot be overridden.

no throws in C#.

throw is used to re-throw exceptions

if we have different layers like Dataaccess layer,Business layer ,Presentation layer. The error is in DataAccess layer,that error should come to presentation layer and we can show that error in messa...

C. Dictionary

Enum is not a collection but a distinct type like struct

All collections directly or indirectly should implement the ICollection interface or the ICollection(Of T) generic interface. If you check System.Array you will see ICollection interface in there. Co...

Object based languages do not support inheritance & dynamic binding. Example, VB

Object Oriented - supports of using the objects.
Object Based Language - all data types are objects, based on single type object primitive.

If any of the methods do not have implementation.

When you do not want to create an object of the class and want to provide some abstract implementation

ex: Class HumanBeing. No Point of creating a class human being. You can create Men or Women out of it an create an object of the derived class

Order of call: From child to parent
Order of execution: From parent to child

Bottom up.

A parent class has no reference to the child class, it's the other way around. The code calls the child class, which then calls the parent class, and so on up. Then the constructors are executed top down.

Not required. If you want your code to be CLS complaint use the annotation CLScompliant(true)

False All .Net code need not be CLS compliant if you are going to write all modules using single .Net language. However, if you are going to use different .Net language for different modules then you...

Comparison operators must be overloaded in pair

Same class name and different parameters within one class

Early binding Or Compile time Or static binding: Assigning of object to type reference happens at compile time.

Late binding Or Run time Or Dynamic binding: Assigning of object to type reference happens at run time.

Early binding is efficient while late binding provides flexibility to programmers.

Early binding is best. Because any errors can be resolved at compile time. Late binding is at Run Time