Latest Interview Questions

1.    What are the main objects in ADO.NET used for data access?

The four main objects of a data provider:-

1)    Connection (This object used to connect a data to a Command object.)
2)    Command object (This object used to connect connection object to Datareader or dataset.)
3)  

1. What do you mean by Object Oriented Programming?

It is a problem solving technique to develop software systems. It’s a technique to think real world in terms of objects. Object maps the software model to real world concept. These objects have responsibilities and provide services to application or other objects.

2. What is a Class?

A class describes all the

Code

try
            {
                try
                {
                    throw new ApplicationException();
                }
                finally
                {
                    throw new SystemException();

                }

            }
            catch (Exception ex)
            {

                Console.WriteLine(ex.GetType().Name);
            }

Output

SystemException.

Reason

When ApplicationException is raise, it will goes to within the  exception stack, and the  finally block also will run and throw system exception, now system exception also goes to within the exception stack.But when we are print within catch, system exception is most recently added, this is will be retrieved first from stack.so SystemException is result for above code.

Answer:

var

If you are use the var keyword, then it valid type against right side value on declaration time

Example:

var data = "name";            
Console.WriteLine(data);

Here var will be string type at compile time.

dynamic

If you are use the dynamic keyword, the type will be decide on run time.

Example:

dynamic data = "name";
data = 8;
Console.WriteLine(data);

it will compile without any error, at run time data variable type is a int than string.because in the second line of code, you have change to string to in value on right hand side.

Answer:

By checking the IsPostBack property. If IsPostBack is True, the page has been posted back.

Example

protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
// code
        }
     }

1. True

Answer:

A delegate object encapsulates a reference to a method. In C++ they were referred to as function pointers.

Answer:

If you want to prevent a class to create subclass, the class must be sealed. Most of the security classes are sealed.

Sample Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    public sealed class TryCatch
    {
        public void SaveEmployee(string empID)
        {

               // few line of code here            
            
        }
    }
}

Answer:

No.if one catch block excuted, then it will directlly go the final block if final block has in method.

Sample Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class TryCatch
    {
        public void SaveEmployee(string empID)
        {
            try
            {
                // few line of code here
            }
            catch (DllNotFoundException dex)
            {
                throw dex;
            }
            catch (Exception)
            {

                throw;
            }
        }
    }
}

above code only execute DllNotFoundException or Generic Exception if any exception occurred.

Answer:

1.Call Sort() method for Array Then

2.Reverse() Method for Array.

Sample Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {

            string[] sample = new string[] { "RRaveen", "John", "Murukan", "Dhan" };            
            Array.Sort(sample);
            Array.Reverse(sample);

            for (int i = 0; i < sample.Length; i++)
            {
                Console.WriteLine(sample[i]);
                
            }
            Console.ReadLine();
         }
     }
}

Output

RRaveen
Murukan
John
Dhan

Answer:

The web service is a common word to communicate platform independent.Web services allow for programmatic access of business logic over the Web. Web services typically rely on XML-based protocols, messages, and interface descriptions for communication and access. Web services are designed to be used by other programs or applications rather than directly by end user. Programs invoking a Web service are called clients. SOAP over HTTP is the most commonly used protocol for invoking Web services.

Answer:

1. A DataSet is designed to work disconnected mode but ADO recordset is always work connected mode.
2. There's no concept of cursor types in a DataSet but ADO RecordSet support to cursor types
3. You can store many data version in a DataSet, and write them to the original data source in a single operation but ADO Recordset does support to more than one version
4. DataSet can contain multiple tables but he RecordSet only one table
5. RecordSet is Required More time than DataSet For data retrival
6. DataSet is always better than the RecordSet compare for best performance.
7. Dataset makes the relationship between the table that belongs in dataset.but there are no concepts like relations in ADO Recordset
8. DataSet support to export many data formats such as XML, HTML and more but ADO Record set not.
9. DataSet can represent an entire relational database in memory, complete with tables, relations, and views.