How to know any website is created on which technology?

http://builtwith.com/

How to know the IP address of any website?

http://en.utrace.de/

How to know the hosting domain of any website?

http://www.whoishostingthis.com/

Removing double/ multiple comma from a string in c#

Use namespace:
using System.Text.RegularExpressions;

then do the following code:

string inputString = "'\"1\":\"C\",\"2\":\"A\",\"3\":\"C\",,\"5\":\"C\",\"6\":\"B\",,\"8\":\"C\",,\"10\":\"C\",'";
string outputString = Regex.Replace(inputString, ",{2,}", ",").Trim(',');

Count Stored Procedures, System Tables, User Defined Tables in any database

USE DATABASENAME

SELECT 
    CASE TYPE 
        WHEN 'U' 
            THEN 'User Defined Tables' 
        WHEN 'S'
            THEN 'System Tables'
        WHEN 'IT'
            THEN 'Internal Tables'
        WHEN 'P'
            THEN 'Stored Procedures'
        WHEN 'PC'
            THEN 'CLR Stored Procedures'
        WHEN 'X'
            THEN 'Extended Stored Procedures'
    END, 
    COUNT(*)     
FROM SYS.OBJECTS
WHERE TYPE IN ('U', 'P', 'PC', 'S', 'IT', 'X')
GROUP BY TYPE