This document discusses HTML forms and how they are used to send data to a server. It explains the GET and POST methods for sending form data, as well as the PHP superglobal variables ($_GET, $_POST, $_REQUEST) that are used to collect the data on the server side. The GET method appends data to the URL and has limitations on size, while the POST method embeds data in the HTTP request body and has no size limits, making it more secure for sensitive data. Both methods create arrays of key-value pairs from the form fields to populate the respective superglobal variables.

1. Course Instructor: Nisa Soomro
Prog_nisa@quest.edu.pk
nisa1207@gmail.com

2.  $_GET
 $_POST
 $_REQUEST
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3.  HTML forms are used to pass data to a server via different input controls.
 All input controls are placed in between <form> and </form>
Syntax
<form action=“PagetoOpen ” method=“ ” >
//input controls placed here
</form>
Method= GET or POST
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<form method="post" action="" >
First Name <input name="fname" type="text" /> <br />
Last Name <input name="lname" type="text" /> <br />
<input type="submit" value="Save" />
</form>

6. The GET Method
 The GET method sends the encoded user information appended to the page request.
The page and the encoded information are separated by the ? character.
 The GET method is restricted to send upto 1024 characters only.
 Never use GET method if you have password or other sensitive information to be sent
to the server.
 GET can't be used to send binary data, like images or word documents, to the server.

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POST Method
 The POST method does not have any restriction on data size to be sent.
 The POST method can be used to send ASCII as well as binary data.
 The data sent by POST method goes through HTTP header so security depends on
HTTP protocol. By using this method your information is secure.

8.  The predefined $_GET Variable use to collect values in a form with method=“get”
information sent from a form with the GET method is visible to everyone (it will
be displayed in the browser address bar ) and has limits on the amount of
information to send.
 $_GET Variable to collect form data ( the name of the form field will automatically
be the keys in the $_GET array )
 $_GET[“name”];
 $_GET[“fname”];
 $_GET[“age”];
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9.  The predefined $_POST Variable use to collect values in a form with
method=“post” information sent from a form with the POST method is invisible to
other and has no limits on the amount of information to send.
 Note: there is an 8MB max size for the POST Method , by default (can be changed
by setting the post_max_size in the php.ini file )
 $_POST Variable to collect form data ( the name of the form field will
automatically be the keys in the $_POST array )
 $_POST[“name”];
 $_POST[“fname”];
 $_POST[“age”];
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10.  The PHP $_REQUEST variable contains the contents of both
$_GET, $_POST, and $_COOKIE. We will discuss $_COOKIE
variable when we will explain about cookies.
 The PHP $_REQUEST variable can be used to get the result from
form data sent with both the GET and POST methods.
 $_REQUEST[“name”];
 $_REQUEST[“fname”];
 $_REQUEST[“age”];
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11.  Both GET and POST create an array (e.g. array( key => value, key2 =>
value2, key3 => value3, ...)). This array holds key/value pairs, where keys
are the names of the form controls and values are the input data from the
user.
 Both GET and POST are treated as $_GET and $_POST. These are
superglobals, which means that they are always accessible, regardless of
scope - and you can access them from any function, class or file without
having to do anything special.
 $_GET is an array of variables passed to the current script via the URL
parameters.
 $_POST is an array of variables passed to the current script via the HTTP
POST method. 11

12.  Information sent from a form with the GET method is visible to everyone (all
variable names and values are displayed in the URL). GET also has limits on the
amount of information to send. The limitation is about 2000 characters. However,
because the variables are displayed in the URL, it is possible to bookmark the
page. This can be useful in some cases.
 GET may be used for sending non-sensitive data.
 Note: GET should NEVER be used for sending passwords or other sensitive
information!
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13.  Information sent from a form with the POST method is invisible to others (all
names/values are embedded within the body of the HTTP request) and has no
limits on the amount of information to send.
 Moreover POST supports advanced functionality such as support for multi-part
binary input while uploading files to server.
 However, because the variables are not displayed in the URL, it is not possible to
bookmark the page.
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14.  www.w3school.com
 http://www.tutorialspoint.com/php/index.htm
 http://www.w3schools.com/php/php_ref_string.asp
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