.Net Interview Questions
21.Does c# support multiple inheritance?
No,its impossible which accepts multi level inheritance.
22. What is ENUM?
Enum are used to define constants.
23. What is a data set?
A DataSet is an in memory representation of data loaded from any data source.
24. What is the difference between private and public keyword?
Private: The private keyword is the default access level and most restrictive among all other access levels. It gives least permission to a type or type member. A private member is accessible only within the body of the class in which it is declared.
Public: The public keyword is most liberal among all access levels, with no restrictions to access what so ever. A public member is accessible not only from within, but also from outside, and gives free access to any member declared within the body or outside the body.
25. Define polymorphism?
Polymorphism means one name, multiple forms. It allows us to have more than one function with the same name in a program. It allows us to have overloading of operators so that an operation can exhibit different behaviors in different instances.
26. What is Jagged Arrays?
A jagged array is an array whose elements are arrays.
The elements of a jagged array can be of different dimensions and sizes.
A jagged array is sometimes called an array–of–arrays.
27. What is an abstract base class?
An abstract class is a class that is designed to be specifically used as a base class. An abstract class contains at least one pure virtual function.
28. How is method overriding different from method overloading?
When overriding a method, you change the behavior of the method for the derived class. Overloading a method simply involves having another method with the same name within the class.
29. What is the difference between ref & out parameters?
An argument passed to a ref parameter must first be initialized. Compare this to an out parameter, whose argument does not have to be explicitly initialized before being passed to an out parameter.
30. What is the use of using statement in C#?
The using statement is used to obtain a resource, execute a statement, and then dispose of that resource.
31.What is serialization?
Serialization is the process of converting an object into a stream of bytes.
De-serialization is the opposite process of creating an object from a stream of bytes.
Serialization / De-serialization is mostly used to transport objects.
32. What are the difference between Structure and Class?
Structures are value type and Classes are reference type
Structures can not have contractors or destructors.
Classes can have both contractors and destructors.
Structures do not support Inheritance, while Classes support Inheritance.
33. What is difference between Class And Interface?
Class is logical representation of object. It is collection of data and related sub procedures with defination.
Interface is also a class containg methods which is not having any definations.Class does not support multiple inheritance. But interface can support.
34. What is Delegates?
Delegates are a type-safe, object-oriented implementation of function pointers and are used in many situations where a component needs to call back to the component that is using it.
35. What is Authentication and Authorization?
Authentication is the process of identifying users. Authentication is identifying/validating the user against the credentials (username and password).
Authorization performs after authentication. Authorization is the process of granting access to those users based on identity.
Authorization allowing access of specific resource to user.
36. What is a base class?
A class declaration may specify a base class by following the class name with a colon and the name of the base class. omitting a base class specification is the same as deriving from type object.
37. Can “this” be used within a static method?
No ‘This’ cannot be used in a static method. As only static variables/methods can be used in a static method.
38. What is difference between constants, readonly and, static ?
Constants: The value can’t be changed.
Read-only: The value will be initialized only once from the constructor of the class.
Static: Value can be initialized once.
39. What are the different types of statements supported in C#?
C# supports several different kinds of statements are
Block statements
Declaration statements
Expression statements
Selection statements
Iteration statements
Jump statements
Try catch statements
Checked and unchecked
Lock statement
40. What is an interface class?
It is an abstract class with public abstract methods all of which must be implemented in the inherited classes.
21.Does c# support multiple inheritance?
No,its impossible which accepts multi level inheritance.
22. What is ENUM?
Enum are used to define constants.
23. What is a data set?
A DataSet is an in memory representation of data loaded from any data source.
24. What is the difference between private and public keyword?
Private: The private keyword is the default access level and most restrictive among all other access levels. It gives least permission to a type or type member. A private member is accessible only within the body of the class in which it is declared.
Public: The public keyword is most liberal among all access levels, with no restrictions to access what so ever. A public member is accessible not only from within, but also from outside, and gives free access to any member declared within the body or outside the body.
25. Define polymorphism?
Polymorphism means one name, multiple forms. It allows us to have more than one function with the same name in a program. It allows us to have overloading of operators so that an operation can exhibit different behaviors in different instances.
26. What is Jagged Arrays?
A jagged array is an array whose elements are arrays.
The elements of a jagged array can be of different dimensions and sizes.
A jagged array is sometimes called an array–of–arrays.
27. What is an abstract base class?
An abstract class is a class that is designed to be specifically used as a base class. An abstract class contains at least one pure virtual function.
28. How is method overriding different from method overloading?
When overriding a method, you change the behavior of the method for the derived class. Overloading a method simply involves having another method with the same name within the class.
29. What is the difference between ref & out parameters?
An argument passed to a ref parameter must first be initialized. Compare this to an out parameter, whose argument does not have to be explicitly initialized before being passed to an out parameter.
30. What is the use of using statement in C#?
The using statement is used to obtain a resource, execute a statement, and then dispose of that resource.
31.What is serialization?
Serialization is the process of converting an object into a stream of bytes.
De-serialization is the opposite process of creating an object from a stream of bytes.
Serialization / De-serialization is mostly used to transport objects.
32. What are the difference between Structure and Class?
Structures are value type and Classes are reference type
Structures can not have contractors or destructors.
Classes can have both contractors and destructors.
Structures do not support Inheritance, while Classes support Inheritance.
33. What is difference between Class And Interface?
Class is logical representation of object. It is collection of data and related sub procedures with defination.
Interface is also a class containg methods which is not having any definations.Class does not support multiple inheritance. But interface can support.
34. What is Delegates?
Delegates are a type-safe, object-oriented implementation of function pointers and are used in many situations where a component needs to call back to the component that is using it.
35. What is Authentication and Authorization?
Authentication is the process of identifying users. Authentication is identifying/validating the user against the credentials (username and password).
Authorization performs after authentication. Authorization is the process of granting access to those users based on identity.
Authorization allowing access of specific resource to user.
36. What is a base class?
A class declaration may specify a base class by following the class name with a colon and the name of the base class. omitting a base class specification is the same as deriving from type object.
37. Can “this” be used within a static method?
No ‘This’ cannot be used in a static method. As only static variables/methods can be used in a static method.
38. What is difference between constants, readonly and, static ?
Constants: The value can’t be changed.
Read-only: The value will be initialized only once from the constructor of the class.
Static: Value can be initialized once.
39. What are the different types of statements supported in C#?
C# supports several different kinds of statements are
Block statements
Declaration statements
Expression statements
Selection statements
Iteration statements
Jump statements
Try catch statements
Checked and unchecked
Lock statement
40. What is an interface class?
It is an abstract class with public abstract methods all of which must be implemented in the inherited classes.