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Unit 10: Cookies
27: <option value=”Hal 2000”>Hal 2000</option> Notes
28: <option value=”Tardis”>Tardis</option>
29: <option value=”ORAC”>ORAC</option>
30: <option value=”Transporter bracelet”>Transporter
bracelet</option>
31: </select>
32:
33: <P><input type=”submit” value=”choose”></p>
34: </form>
35:
36: <p><a href=”listing10.5.php”>go to content page</a></p>
37: </body>
38: </html>
We start or resume a session by calling session_start() on line 2. This should give us
access to any previously set session variables. We begin an HTML form on line 23 and, on line
25, create a SELECT element named form_products[], which contains OPTION elements
for a number of products. Remember that HTML form elements that allow multiple selections
should have square brackets appended to the value of their NAME arguments. This makes the
user’s choices available in an array.
Within the block of PHP code beginning on line 10, we test for the presence of the $_
POST[form_products] array (line 11). If the variable is present, we can assume that the form
has been submitted and information has already been stored in the $_SESSION superglobal.
We then test for an array called $_SESSION[products] on line 12. If the array exists, it was
populated on a previous visit to this script, so we merge it with the $_POST[form_products]
array, extract the unique elements, and assign the result back to the $products array (lines
13–15). We then add the $products array to the $_SESSION superglobal on line 16.
Line 36 contains a link to another script, which we will use to demonstrate our access to the
products the user has chosen. We create this new script in example.
Example: 5: Accessing Session Variables
1: <?php
2: session_start();
3: ?>
4: <html>
5: <head>
6: <title>Listing 10.5 Accessing session variables</title>
7: </head>
8: <body>
9: <h1> Content Page</h1>
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