PHP Undefined offset Message when using "list" function - php

Question

I got this error on my website this morning when I click on post-ad
I have tried looking at the code but don't seem to find anything wrong
if (!function_exists('adforest_extarct_link')) {
function adforest_extarct_link($string) {
$arr = explode('|', $string);
list($url, $title, $target, $rel) = $arr; /* This is line 148 */
$rel = urldecode(adforest_themeGetExplode($rel, ':', '1'));
$url = urldecode(adforest_themeGetExplode($url, ':', '1'));
$title = urldecode(adforest_themeGetExplode($title, ':', '1'));
$target = urldecode(adforest_themeGetExplode($target, ':', '1'));
return array("url" => $url, "title" => $title, "target" => $target, "rel" => $rel);
}
This is the error Message
Undefined offset: 3 in /customers/7/6/1/corpersmarket.com/httpd.www/wp-content/themes/adforest/inc/theme_shortcodes/short_codes_functions.php on line 148
It actually has 3 lines of error:
Notice: Undefined offset: 1 in /customers/7/6/1/corpersmarket.com/httpd.www/wp-content/themes/adforest/inc/theme_shortcodes/short_codes_functions.php on line 148
Notice: Undefined offset: 2 in /customers/7/6/1/corpersmarket.com/httpd.www/wp-content/themes/adforest/inc/theme_shortcodes/short_codes_functions.php on line 148
Notice: Undefined offset: 3 in /customers/7/6/1/corpersmarket.com/httpd.www/wp-content/themes/adforest/inc/theme_shortcodes/short_codes_functions.php on line 148

Answer 1

Question is broadly a duplicate of PHP undefined offset from list()
However,
Your list expects at least 4 prameters -- but your $arr array only has 1. So the following three are empty. (remember arrays start at 0). So your $string does not contain a | character for the explode function to work as intended.
Workaround:
Original:
$arr = explode('|', $string);
list($url, $title, $target, $rel) = $arr; /* This is line 148 */
Becomes:
$arr = array_pad(explode('|', $string), 4, null);
list($url, $title, $target, $rel) = $arr;
What this does:
Pads the array out to contain a minimum of 4 values; so that the list values will always be populated, even if they may still be empty.