Win Surprise Gifts!!!
Top 5 Contributors of the Month
Post New Question
Subscribe to Interview Questions
Can a constructor could be abstract in c#?
Posted By :
Posted Date :
April 27, 2011
No, a constructor can not be abstract in c#
You can also find related Interview Question to
Can a constructor could be abstract in c#?
Difference between type constructor and instance constructor? What is static constructor, when it will be fired? And what is its use?
(Class constructor method is also known as type constructor or type initializer)
Instance constructor is executed when a new instance of type is created and the class constructor is executed after the type is loaded and before any one of the type members is accessed. (It will get executed only 1st time, when we call any static methods/fields in the same class.) Class constructors are used for static field initialization. Only one class constructor per type is permitted, and it cannot use the vararg (variable argument) calling convention.
What is Private Constructor? and it's use? Can you create instance of a class which has Private Constructor?
When a class declares only private instance constructors, it is not possible for classes outside the program to derive from the class or to directly create instances of it. (Except Nested classes)
Make a constructor private if:
1) You want it to be available only to the class itself. For example, you might have a special constructor used only in the implementation of your class' Clone method.
2) You do not want instances of your component to be created. For example, you may have a class containing nothing but Shared utility functions, and no instance data. Creating instances of the class would waste memory.
What is the difference between interface and abstract class ?
a class may inherit several interfaces, a class may inherit only one abstract class
C# provides a default constructor for me. I write a constructor that takes a string as a parameter, but want to keep the no parameter one. How many constructors should I write?
The answer is TWO of the above questions
What are Abstract base classes?
Abstact Class is nothing but a true virtual class..
This class cannot be instantiated instead it has to be inherited.
The method in abstract class are virtual and hence they can be overriden in the child class.
What is difference between abstract class and an interface?
An Abstract class is a class with some common/certain implementations and defines abstraction for other services which are implemented in its concrete sub classes, whereas interface only have method declaration with zero implementations. An abstract class and Interface both have method only but not have body of method. The difference between Abstract class and An Interface is that if u call Abstract class then u have to call all method of that particular Abstract class but if u call an Interface then it is not necessary that u call all method of that particular interface. An abstract class is a special kind of class that cannot be instantiated. So the question is why we need a class that cannot be instantiated? An abstract class is only to be sub-classed (inherited from). In other words, it only allows other classes to inherit from it but cannot be instantiated. The advantage is that it enforces certain hierarchies for all the subclasses. In simple words, it is a kind of contract that forces all the subclasses to carry on the same hierarchies or standards.
An interface is not a class. It is an entity that is defined by the word Interface. An interface has no implementation; it only has the signature or in other words, just the definition of the methods without the body. As one of the similarities to Abstract class, it is a contract that is used to define hierarchies for all subclasses or it defines specific set of methods and their arguments. The main difference between them is that a class can implement more than one interface but can only inherit from one abstract class. Since C# doesn't support multiple inheritance, interfaces are used to implement multiple inheritance.
Constructor and Destructor
1. The Constructor is the first method that is run when an instance of a type is created. In visual basic a constructor is always Sub new ().
2. Constructor are use to initialize class and structure data before use. Constructor never returns a value and can be overridden to provide custom initialization functionality.
3. The constructor provides a way to set default values for data or perform other necessary functions before the object available for use.
Destructors are called just before an object is destroyed and can be used to run clean-up code. You can't control when a destructor is called.
What is a private constructor? Where will you use it?
When you declare a Constructor with Private access modifier then it is called Private Constructor. We can use the private constructor in singleton pattern.
If you declare a Constructor as private then it doesn't allow to create object for its derived class, i.e you loose inherent facility for that class.
When do you have to declare a class as abstract?
1. When the class itself is inherited from an abstract class, but not all base abstract methods have been overridden.
2. When at least one of the methods in the class is abstract.
What is Static Constructor?
It is invoked when the instance of the class is created.
What exactly a Constructor is doing ?
Constructor Creates as well as Initialized the objects.
What is the work of a constructor?
Constructor creates and initialises the objects in an application.
A constructor can be private. True or False
False. A constructor should not be private.
Static datamembers should be initialized inside the constructor. True or False.
False. Static datamembers should not be initialised inside constructor.
Quick Links For Interview Questions Categories:
Find questions, FAQ's and their answers related to .NET, C#, Vb.Net, Sql Server and many more.
Now you can find lots of .NET, C#, Vb.Net, SQL Server,Windows, ASP.Net related Questions and their Answers here at www.dotnetspark.com. Our aim is to help you pass your certification Exams (MCP, MCSD, MCAD etc.,) with flying scores and get good name in your company.
So, Start looking our
section daily and improve your .NET Skills. You can also help others by posting Interview Questions and their Answers in this section.
Hall of Fame
Terms of Service
Tell A Friend