sometimes the following notice is displayed when accessing array:

PHP Notice: Undefined offset [number] in /path/to/your/file.php on line [number]

or this:

PHP Notice: Undefined index [number] in /path/to/your/file.php on line [number]

this means the array key / index does not exist in the array.

it's worthwhile to check with print_r() to see what's in the array.

usually errors at notice level have no major impact to the functionality of the code. it can be turned off with error_reporting() (recommend for production):

error reporting(E_ALL & ~E_NOTICE);

however it's better not to turn this off at development level and try to fix it. check if the key exists with isset(). if using list() with explode() for string that may return variable array size:

@list($var1, $var2, $var3) = explode(':', $string);