Saturday, January 5, 2013

$_GET and $_POST in PHP


Introduction
Using the GET and POST methods, the browser client can send data to the web server. In PHP the GET and POST methods are used to retrieve information from forms, such as user input. Get and Post are methods used to send data to the server. These methods are used for data handling in forms.  Where each method varies a little in the way they work.
GET Method
In the GET method, we can also send data to the server. But when using the GET method we can't send the login details with a password because it is less secure (information sent from a form with the GET method is visible to everyone). We can say that the GET method is for getting something from the server; it doesn't mean that you cannot send a parameter to the server.
The main points about the GET method are as follows:
  • The GET method is used to collect values in a form.
  • GET method is used when the URL is sent to the server.
  • GET method has limits on the amount of information to send because URL lengths are limited.
  • The Get method is used to retrieve web pages from the server.
  • The GET method is the default method for many browsers.
  • Data is sent as a part of the URL in 'name-value' pairs.
  • In the GET method page and the encoded information are separated by the question mark  (?) sign.
  • In the GET method, the browser appends the data onto the URL.
  • The Get method is less secure because information sent from a form with the GET method is visible to everyone (it will be displayed in the browser's address bar) .
  • GET can't be used to send binary data, like images or word documents, to the server.
Example
First of all we create a PHP file which is called by the HTML page in later.

<
body bgcolor="pink">Welcome echo $_GET ["Name"]; ?>.<br/>You are echo $_GET ["Class"]; ?> Qualified !!</body>
The above file is to be saved with the name "get.php", which is called by the HTML page later.

<
body bgcolor="pink"><table>
<
form action="get.php" method="get"><tr><td>Name: <input type="text" name="Name" /></td></tr><tr><td>Class : <input type="text" name="Class" /></td></tr><input type="submit" " value="Submit"/></form> </body>
This file is saved as "get.html". In this file get.php is called.
Output
You will put the URL in the web browser like as: http://localhost/FolderName/get.html.
image1.jpg
Now you will fill text like as name and class. When you click on the submit button then you will see your browser URL changed. You can see in the following image.
image2.jpg
POST Method
In PHP $_POST variable is used to collect values from a form sent with method="post". In the POST method one can request as well as send some data to the server. The POST method is used when one can send a long enquiry form. Using the POST method the login details with password can be posted because it is secure (information sent from a form with the POST method is invisible to everyone).
The main points about POST method are as follows:
  • The POST method is used to collect values from a form.
  • The POST method has no limits on the amount of information to send because URL lengths are unlimited.
  • The POST method is the not default method for many browsers.
  • In the POST method, the page and the encoded information are not separated by the question mark  (?) sign.
  • In the POST method, the browser doesn't append the data onto the URL.
  • The POST method is secure because information sent from a form with the GET method is invisible to everyone.
  • The POST method can be used to send binary data, like images or Word documents, to the server.
  • In the POST method, the data is sent as standard input.
  • The POST method is slower than the GET method.
  • PHP provides the $_POST associative array to access all the information sent using the GET method.
Example
First of all we create a PHP file which is called by the HTML page later.

<
body bgcolor="pink">Welcome echo $_POST ["Name"]; ?>.<br/>You are echo $_POST ["Class"]; ?> Qualified !!</body>
The above file is saved with the "post.php" name, which is called by the HTML page later.

<
body bgcolor="pink"><table>
<
form action="post.php" method="post"><tr><td>Name: <input type="text" name="Name" /></td></tr><tr><td>Class : <input type="text" name="Class" /></td></tr><input type="submit" " value="Submit"/></form> </body>
This file is saved as "post.html". In this file post.php is called.
image3.jpg
Now you will fill text like as name and class. When you click on the submit button then you will see your browser URL is not changed. You can see in the following image.
image4.jpg

$_REQUEST Variable

The $_REQUEST variable is also used to send data to the server. The $_REQUEST variable is a predefined variable in PHP. Which keeps the $_GET, $_POST and also $_Cookie variable. This variable is used to collect data of the form sent by the GET and POST methods.
First of all we create a PHP file which is called by the HTML page later. 

<
body bgcolor="pink">Welcome echo $_REQUEST ["Name"]; ?>.<br/>You are echo $_REQUEST ["Class"]; ?> Qualified !!</body>
The above file is saved with the "request.php" name, which is called by the HTML page later.

<
body bgcolor="pink"><table>
<
form action="request.php" method="post"><tr><td>Name: <input type="text" name="Name" /></td></tr><tr><td>Class : <input type="text" name="Class" /></td></tr><input type="submit" " value="Submit"/></form> </body>
This file is save as "request.html". In this file post.php is called.
image5.jpg
If we use the POST method then the URL of the browser is not append. You can see in the following image.
image6.jpg
If we use the GET method then the URL of the browser is changed. You can see in the following image.
image7.jpg
Conclusion
So in this article you saw the differences between the GET and POST methods in PHP.

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