Variables from outside PHP

HTML Forms (GET and POST)

When a form is submitted to a PHP script, any variables from that form will be automatically made available to the script by PHP. If the track_vars configuration option is turned on, then these variables will be located in the associative arrays $HTTP_POST_VARS, $HTTP_GET_VARS, and/or $HTTP_POST_FILES, according to the source of the variable in question.

For more information on these variables, please read Predefined variables.

Example 7-1. Simple form variable <form action="foo.php" method="post"> Name: <input type="text" name="username"><br> <input type="submit"> </form>

When the above form is submitted, the value from the text input will be available in $HTTP_POST_VARS['username']. If the register_globals configuration directive is turned on, then the variable will also be available as $username in the global scope.

PHP also understands arrays in the context of form variables. You may, for example, group related variables together, or use this feature to retrieve values from a multiple select input:

Example 7-2. More complex form variables <form action="array.php" method="post"> Name: <input type="text" name="personal[name]"><br> Email: <input type="text" name="personal[email]"><br> Beer: <br> <select multiple name="beer[]"> <option value="warthog">Warthog <option value="guinness">Guinness <option value="stuttgarter">Stuttgarter Schwabenbräu </select> <input type="submit"> </form>

In PHP 3, the array form variable usage is lim