C#: System data types

C# Shorthand	System Type	Range	Meaning in life
sbyte	System.Sbyte	-128 to 127	Signed 8-bit number
byte	System.byte	0 to 255	Unsigned 8-bit number
short	System.Int16	-32.768 to 32.767	Signed 16-bit number
ushort	System.UInt16	0 to 65.535	Unsigned 16-bit number
int	System.Int32	-2.147.483.648 to 2.147.483.647	Signed 32-bit number
uint	System.UInt32	0 to 4,294,967,295	Unsigned 32-bit number
long	System.Int64	–9,223,372,036,854,775,808 to 9,223,372,036,854,775,807	Signed 64-bit number
ulong	System.UInt64	0 to 18,446,744,073,709,551,615	Unsigned 64-bit number
char	System.Char	U0000 to Uffff	A single 16-bit Unicode character
float	System.Single	1.5x10-45 to 3.4x1038	32-bit floating point number
double	System.Double	5.0x10-324 to 1.7x10308	64-bit floating point number
bool	System.Boolean	true or false	Represents truth or falsity
decimal	System.Decimal	100 to 1028	A 96-bit signed number
string	System.String	Limited by system memory	Represents a set of Unicode characters
object	System.Object	Any type can be stored in an object variable	The base class of all types in the .NET universe

PHP: Validating email address.

function emailValidate($email)
{
   if(!eregi("^[a-z]+[a-z0-9_-]*(\.[a-z0-9_-]+)*@[a-z0-9]+
      (\.[a-z0-9_-]+)*\.(\.[a-z]+){2,}$",$email))
  {
      return true;
  }
  return false;
}

eregi case insensitive regular expression math.

log2( x ): Binary Logarithm

In the math.h of Turbo C, binary logarithm ( log2( ) ) doesn't exists. When we are working with tree, we need to calculate depth of the tree, as well as the number of nodes in that depth.
The number of nodes in ith depth can be calculated using : 2ⁱ . formula
the max number of node in ith depth : n = 2ⁱ - 1 (complete tree).
You can use these formula to find the number of nodes in particular depth.

On the other hand, you may need to find the depth you are currently in.
There is a very easy way to do that. This is using binary logarithm to find the current depth.

...
#include <math.h>
double log2(double x)
{
       return log(x) / log(2);
}

If i made mistakes let me know
Good luck

PHP: data grid view

Lets demonstrate how to show data in data grid view using php.
When we are working on website, one of the most important things is to show the data in brief and in a nice way
To do that combining HTML tags along with php.

Now lets see small example

Binary Search

Very useful searching algorithm, in every step the number of data, which is going to be sorted will cut into half (fig 1). But keep it in your mind that it works on only sorted data.
Let N be the number of data then,
in worst case the comparison will be done log₂(N) + 1 times. And in case of linear searching, the number of comparison would be N.
For example: if we are going to search a number among a million others, in the worst case scenario, the number of comparison would never be exceeded 20. But in case of linear searching algorithm, the number of comparison would be 1.000.000

Source code :

Indian Wedding (Photos)

This is the wedding of one of the biggest college's principal's daughter. There was everything that you could possible eat in India, Most important thing is that they are all free hehe. I mean food

PHP : Login Page

Here is simple guide to create login page. About design, you can create one as you like using html. This is simple design that i created to demonstrate how login page works. You can use just two text-boxes and submit button, that is all.

Make sure that your text-boxes and submit button are inside the "Form" which uses method field and action field as shown below.

<Form name="Form1" method="post" action="login.php"> ...

When you hit login or submit button, all data which are inside this form will be thrown to login.php.
And they won't appear in address bar. Because method is post.