datetime format in c#

Function                                                    Shows

DateTime.Now.TimeOfDay()                    13:39:21.0363750
DateTime.Now.ToShortTimeString()        1:39 PM
DateTime.Now.ToString("HH:mm ss tt") 13:39 21 PM
DateTime.Now.ToString("hh:mm ss tt")   01:39 21 PM
DateTime.Now.ToString("HHmm")          1339   

What is the Parent Class of Server controls ?

System.Web.Ul.Control

How to pass '&' in QueryString?

We can use %26 for '&' symbol in QueryString,

There is another way using URL Encode

string members="mom & dad";
Response.Redirect("family.aspx?mem="+ Server.UrlEncode(members));

What is the Maximum length of QueryString?

Maximum length of Querystring is based on the browser not depend upon the asp.net.

• Maximum length of a querystring in IE 4.0 and above is ~2048 characters
• IE. 4,5,6,7, - 2,048 characters.
• Opera supports - 4050 characters.
• Netscape 6 supports - 2000 characters.Firefox Supports - 6000 characters 

State Management Techniques

The following are the commonly used state management techniques.

• QueryString
• Coockies
• Cache
• ViewState
• Session state
• Application state
• Static variables
• Profiles 

 Query String:

Query String will looks like

www.aspnet.com/article.aspx?id=1

In URL which comes after ? symbol is called QueryString.It will be having key,value pair.

In above example 'id' is the key and '1' is the value.we can send multiple values using QueryString

Response.Redirect("www.aspnet.com/article.aspx?id=1&name=satya");

In article.aspx page we can get id and name values as follows

Request.QueryString["id"];
Request.QueryString["name"];

It is most useful State Management technique,It is very easy to use,it will not consume any server side resources.

Disadvantages:

• URL length limitation is there,we can't send more information through URL.
• Information send through URL can be visible to anyone,and can be easily altered.

Cookies:

Cookies are Client Side State Management technique.

In ASP.NET we will create Cookies using HttpCookie class.Using Response,Request objects we will add and retrieve Cookies respectively.

Create Cookie:

Response.Redirect["id"].Value="10"

It will stay till browser closes,once browser colsed Cookie will expire.We can create Cookie which will stay based on time.

By making use of HttpCookie.Expires property we can set the expiry date.See below

Response.Cookies["id"].Value="10";
Response.Cookies["id"].Expires=DateTime.Now.AddDays(1);

so that 'id' value will be statying till one day.If we want to remove before that expiry date ,we need to write Expires statement once again as follows

Response.Cookies["id"].Expires=DateTime.Now.AddDays(-1);

Reading the Cookie Values:

Request.Cookies["id"].Value;

Restriction Operators

Where:

Using where we can filter the records in a particular set based on some condition.

EX:

For example take one array set of numbers

int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };

Suppose if we want to find the elements which are less than 5 in the above set.How to achieve this using where condition in LINQ.

Declare one variable and using the where condition to above set ,store the values in variable.

var lowNums = from n in numbers where n < 5 select n;

Now lowNums is having values less than 5

code:
 public void whereSimple1()
        {
            int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };

            var lowNums = from n in numbers where n < 5 select n;

            Console.WriteLine("Numbers <5:");
            foreach (var x in lowNums)
            {
                Console.WriteLine(x);
            }
            Console.ReadKey();
        }

output:

Numbers <5:

4
1
3
2
0

Types of Operators in LINQ

The following types of Operators existed in LINQ

• Restriction Operators
• Projection Operators
• Partitioning Operators
• Ordering Operators
• Grouping Operators
• Set Operators
• Conversion Operators
• Element Operators
• Generation Operators
• Quantifiers
• Aggregate Operators
• Miscellaneous Operators
• Custom Sequence Operators
• Query Execution
• Query Execution

What is Common Language Runtime?

Writing programs in any of visual basic, visual c++, or c# languages and compile their programs into an intermediate form of code are called Common Intermediate Language (CIL), it is managed and executed by Common Language Run time. First after compilation of initial language, information will be getting stored in metadata, this metadata tells the CLR what language was used including its version and also what all class libraries required for this program.

what is the difference between String Builder and string?

String Builder is useful when need to build strings in multiple steps.

EX:

String:

 String x="";
 x +="michael";
 x +="jackson";

String Builder:

 StringBuilder sbObj=new StringBuilder("");
 sbObj.Append("michael");
 sbObj.Append("jackson");
 String x=sbObj.Tistring();

Both will give the same results but StringBuilder will take less memory and runs faster.String each time it will create new instance where as StringBuilder will create chunks and add only add at the end it will unite it.

what is the diffrence between ASP and ASP.NET?

The main diffrence between ASP and ASP.NET is ASP is interprtted language where as ASP.NET is compiled. Asp uses scripting language(VB Script) where as ASP.NET uses languages like c#,VB..etc..which are compiled to Microsoft Intermediate Language(MSIL).