.NET Interview Questions and Asnwers for 2023

Introduction

If you are going for a .NET interview, you may want to read these .NET interview questions and their answers.

1. What is the sequence of execution of the ASP.NET page life cycle?

The simple way is to remember SILVER.

• S (It is not counted)
• I (Init)
• L (Load)
• V (Validate)
• E (Event)
• R (Render)

Read more here.

2. What is the difference between a Hash Table and a Dictionary?

The main differences are listed below.

Dictionary,

• Returns an error if the key does not exist
• No boxing and unboxing
• Faster than a Hash table

Hashtable,

• Returns NULL even if the key does not exist
• Requires boxing and unboxing
• Slower than a Dictionary

3. How to use View state?

string str = "Sibeesh Passion";  
if(ViewState["SampleText"]==null)  
{  
   ViewState["SampleText"] = str;  
}

4. What are the state management techniques used in .NET?

Client-side

• Hidden Field
• View State
• Cookies
• Control State
• Query Strings

Server-side

• Session
  
  1. In Proc mode
  2. State Server mode
  3. SQL Server mode
  4. Custom mode
     
• Application.

Read here.

5. How can we create a new table in SQL with only the structure?

Here is the query to do that.

Select * Into<B>From<A>Where1 = 2

Points to be noted:

• A is the source table.
• B is the destination table.
• Condition 1=2 is to prevent the data from being copied.

6. How to add a button dynamically to a grid view?

Button myButton = newButton();  
myButton.Text = "Hai";  
myGrid.Controls.Add(myButton); 

7. How to find a control inside a GridView?

Button btnTest = (Button) myGrid.Rows[0].Cells[1].Controls[1].FindControl("myButton ");  

Here we are finding the control myButton from the 0th row first cell.

8. What are abstract and interface? Provide actual examples.

Please read here.

9. What is a partial class?

There are the following situations when splitting a class definition is desirable:

• To work with large projects.
• To split the class definitions as we needed with the keyword partial.

10. How to use a partial class?

public partial class DailyExpenses  
{  
    To make it more real, let us consider this class is used by the Husband .   
    He will add his expenses (in programming life , his codes )  
    public void AddExpensesByHus()  
    {  
    }  
}  
public partial class DailyExpenses  
{  
   To make it more real, let us consider this class is used by the Wife.   
   She will add his expenses (in programming life , her codes )  
   public void AddExpensesByWife()  
    {  
    }  
}

11. How to remove a constraint from a table in SQL Server?

ALTER TABLE MyTab DROP CONSTRAINT myConstraint

12. How to create Table Variables In T-SQL?

Normally the syntax to create a table variable is the same as to create a table statement.

DECLARE@tabVar TABLE  
(  
   Your fields here  
)

13. How can you delete a duplicate record from a table in SQL?

There are so many ways to do this. Here I am sharing what I use when I get that kind of situation.

I will create a temp table.

Copy the distinct data from the existing table to the temp table.

Empty the data in the existing table.

Insert the data from the temp table into the source table.

Here is the query to do that:

select distinct * into #tempTab From Address_Tab
delete from Address_Tab
insert into Address_Tab
select * from # tempTab
drop table # tempTab

14. When to use an override and new in C#?

• We can use override when there is a virtual/abstract/override type of method in a base class.
• We can use New when there is no virtual/abstract/override type of method in a base class.

Next readings:

• ASP.NET MVC Interview Questions
• C# interview questions
• SQL Server interview questions