php - How to avoid 'undefined index' errors?

Question

(This question already has answers here): question from:https://stackoverflow.com/questions/1195549/how-to-avoid-undefined-index-errors

Answer 1

Figure out what keys are in the $output array, and fill the missing ones in with empty strings.

$keys = array_keys($output);
$desired_keys = array('author', 'new_icon', 'admin_link', 'etc.');

foreach($desired_keys as $desired_key){
   if(in_array($desired_key, $keys)) continue;  // already set
   $output[$desired_key] = '';
}