PHP - POST & GET
Recall from the PHP Forms Lesson where we used an HTML form and sent it to a PHP web page for processing. In that lesson we opted to use the the
post method for submitting, but we could have also chosen the
get method. This lesson will review both transferring methods.
POST - Review
In our
PHP Forms Lesson we used the
post method. This is what the pertinent line of HTML code looked like:
HTML Code Excerpt:
<form action="process.php" method="post">
<select name="item">
...
<input name="quantity" type="text" />
This HTML code specifies that the form data will be submitted to the "process.php" web page using the POST method. The way that PHP does this is to store all the "posted" values into an
associative array called "$_POST". Be sure to take notice the names of the form data names, as they represent the
keys in the "$_POST" associative array.
Now that you know about associative arrays, the PHP code from "process.php" should make a litte more sense.
PHP Code Excerpt:
$quantity = $_POST['quantity'];
$item = $_POST['item'];
The form names are used as the
keys in the associative array, so be sure that you never have two input items in your HTML form that have the same name. If you do, then you might see some problems arise.
PHP - GET
As we mentioned before, the alternative to the
post method is
get. If we were to change our HTML form to the
get method, it would look like this:
HTML Code Excerpt:
<form action="process.php" method="get">
<select name="item">
...
<input name="quantity" type="text" />
The
get method is different in that it passes the variables along to the "process.php" web page by appending them onto the end of the URL. The URL, after clicking submit, would have this added on to the end of it:
"?item=##&quantity=##"
The question mark "?" tells the browser that the following items are variables. Now that we changed the method of sending information on "order.html", we must change the "process.php" code to use the "$_GET" associative array.
PHP Code Excerpt:
$quantity = $_GET['quantity'];
$item = $_GET['item'];
After changing the array name the script will function properly. Using the
get method displays the variable information to your visitor, so be sure you are not sending password information or other sensitive items with the
get method. You would not want your visitors seeing something they are not supposed to!
