PHP GET and POST Methods
There are two ways the
browser client can send information to the web server.
- The GET Method
- The POST Method
Before the browser sends
the information, it encodes it using a scheme called URL encoding. In this
scheme, name/value pairs are joined with equal signs and different pairs are
separated by the ampersand.
name1=value1&name2=value2&name3=value3
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Spaces are removed and
replaced with the + character and any other non-alphanumeric
characters are replaced with a hexadecimal values. After the information is
encoded it is sent to the server.
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.
http://www.test.com/index.htm?name1=value1&name2=value2
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- The GET method produces a long string that appears in your server logs, in the browser's Location: box.
- 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.
- The data sent by GET method can be accessed using QUERY_STRING environment variable.
- The PHP provides $_GET associative array to access all the sent information using GET method.
Try out following example
by putting the source code in test.php script.
<?php
if(
$_GET["name"] || $_GET["age"] )
{
echo "Welcome ". $_GET['name']. "<br />";
echo "You are ". $_GET['age']. " years old.";
exit();
}
?>
<html>
<body>
<form action="<?php $_PHP_SELF ?>"
method="GET">
Name:
<input type="text" name="name" />
Age:
<input type="text" name="age" />
<input type="submit" />
</form>
</body>
</html>
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The POST method transfers
information via HTTP headers. The information is encoded as described in case
of GET method and put into a header called QUERY_STRING.
- 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 Secure HTTP you can make sure that your information is secure.
- The PHP provides $_POST associative array to access all the sent information using POST method.
Try out following example
by putting the source code in test.php script.
<?php
if(
$_POST["name"] || $_POST["age"] )
{
echo "Welcome ". $_POST['name']. "<br />";
echo "You are ". $_POST['age']. " years old.";
exit();
}
?>
<html>
<body>
<form action="<?php $_PHP_SELF ?>" method="POST">
Name:
<input type="text" name="name" />
Age:
<input type="text" name="age" />
<input type="submit" />
</form>
</body>
</html>
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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.
Try out following example
by putting the source code in test.php script.
<?php
if(
$_REQUEST["name"] || $_REQUEST["age"] )
{
echo "Welcome ". $_REQUEST['name']. "<br
/>";
echo "You are ". $_REQUEST['age']. " years old.";
exit();
}
?>
<html>
<body>
<form action="<?php $_PHP_SELF ?>"
method="POST">
Name:
<input type="text" name="name" />
Age:
<input type="text" name="age" />
<input type="submit" />
</form>
</body>
</html>
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Here $_PHP_SELF variable
contains the name of self-script in which it is being called.
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