Following are the steps to create a simple AD rotator script without using database in PHP:

- All the ad’s can be collected in one place and be displayed randomly.rand() function can be used for this purpose.

- In order to NOT use any database, a flat file can be used to store the ad’s.

- In order to store the Ad’s information (HTML code), a flat file say “ad.txt” can be created.

- The random number can be stored in a variable 

$result_random=rand(1, 100);

- Conditions can be checked to display the ad’s.

if($result_random<=70)

{

      echo "Display ad1";

}

To pass the information into the script from outside, help can be taken from the PHP CLI (Command line interface) method. Suppose addition of two numbers has to be passed to PHP then it can be passed like this on the command line:

php add.php 2 3

Here the script name is add.php, and 2 and 3 are the numbers that has to be added by the script. These numbers are available inside the script in an array called $argv. This array contains all the information on the command line; the statement is stored as follows:

$argv[0]=add.php

$argv[1]=2

$argv[2]=3

So, $argv always contains at least one element — the script name.

Then, in your script, you can use the following statements:

$sum = $argv[1] + $argv[2];

echo $sum;

$argc is a variable that stores the numbers of elements in $argv. $argc is equal to at least 1, which is saved for the name of the script. Example is $argc=3 using the above statements.

$_SERVER and $_ENV arrays contain different information. The information depends on the server and operating system being used. Most of the information can be seen of an array for a particular server and operating system. The syntax is as follows:

foreach($_SERVER as $key =>$value)

{ echo “Key=$key, Value=$value\n”; }

Super global arrays are the built in arrays that can be used anywhere. They are also called as auto-global as they can be used inside a function as well. The arrays with the longs names such as $HTTP_SERVER_VARS, must be made global before they can be used in an array. This $HTTP_SERVER_VARS check your php.ini setting for long arrays.

The difference lies with the execution of the languages. PHP is server side scripting language, which means that it can’t interact directly with the user. Whereas, JavaScript is client side scripting language, that is used to interact directly with the user.

HTTP headers can be used in PHP by redirection which is written as:

<?header('Location: https://www.php.net')?>

The headers can be added to HTTP response in PHP using the header(). The response headers are sent before any actual response being sent. The HTTP headers have to be sent before taking the output of any data. The statement above gets included at the top of the script.

MIME - Multi-purpose Internet Mail Extensions. 

MIME types represents a standard way of classifying file types over Internet. 

Web servers and browsers have a list of MIME types, which facilitates files transfer of the same type in the same way, irrespective of operating system they are working in.

A MIME type has two parts: a type and a subtype. They are separated by a slash (/). 

MIME type for Microsoft Word files is application and the subtype is msword, i.e. application/msword.

echo() and print() are language constructs in PHP, both are used to output strings. The speed of both statements is almost the same.

echo() can take multiple expressions whereas print cannot take multiple expressions.

Print return true or false based on success or failure whereas echo doesn't return true or false.