Using Arrays as Widget Names

As I described in the first section of this chapter, the <SELECT> widget can potentially be used to select multiple items and thus have multiple values to pass to PHP. Unfortunately, setting the NAME attribute to something such as myselect will create a variable $_GET['myselect'], which will contain only the last item selected from the list. Obviously, this is not the desired result and another method must be used. To solve this problem, PHP allows you to dynamically create arrays based on form submissions by appending a set of square brackets [] to the end of the name of the widget. Thus, myselect would become myselect[], causing PHP to create an additional item in the array $_GET['myselect'] instead of overwriting the previous value. This concept is illustrated in :

Listing 4.13. Using Arrays with Form Data in PHP

The HTML code:

<SELECT NAME="myselect[]" MULTIPLE SIZE=3>
<OPTION VALUE="value1">Pick Me!</OPTION>
<OPTION VALUE="value2">No, Pick Me!</OPTION>
<OPTION VALUE="value3">Forget them, pick me!</OPTION>
<OPTION VALUE="value4">Pick me, I'm the best</OPTION>
</SELECT>

The PHP code to access which value(s) were selected:

<?php
     foreach($_GET['myselect'] as $val) {
          echo "You selected: $val<BR>";
     }
     echo "You selected ".count($_GET['myselect'])." Values.";
?>

This technique is not limited to <SELECT> widgets or, for that matter, integer-based arrays. If you would like to provide a string key for a given form widget, specify it (without quotes) within the square brackets:

<INPUT TYPE="text" NAME="data[email]" VALUE="joe.doe@joe.doe.com">

When submitted, the preceding text field's value could be accessed by using $_GET['data']['email'].

Handling File Uploads

As I alluded to in the first section of this chapter, PHP is capable of accepting file uploads from HTML forms via the file widget. When uploading files from an HTML form, some special consideration must be taken regarding the <FORM> tag itself. Specifically, for the file upload to succeed, the ENCTYPE attribute of the <FORM> tag must be set to the MIME value multipart/form-data and the METHOD attribute must be set to POST. An example of an HTML form that uploads a file to the script upload.php is shown in

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