I have also created a small video explaining the private constructor. Do visit my 21 important .NET interview questions and answers.

This is one of those .NET interview question which is asked from the perspective to test if you understand the importance of private constructors in a class.

When we declare a class constructor as private , we can not do 2 things:-

• We can not create a object of the class.
• We can not inherit the class.

Now the next question which the interviewer will ask , whats the use of such kind of class which can not be inherited neither instantiated.

Many times we do not want to create instances of certain classes like utility , common routine classes. Rather than calling as shown below 

clsCommon common = new clsCommon();
common.CheckDate("1/1/2011");

You would like to call it as

clsCommon.CheckDate("1/1/2011");

Check my 21 important .NET interview questions and answers