PHP array_filter: How to Process the Array Values Before Finalization
PHP Tutorial - PHP array_filter() function
array_filter: How to use with examples in PHP - Fueling PHP
PHP array_filter base on keys in JavaScript | Free Online Tutorials
How Array_filter in previous Array (Text) question and Array question result - LimeSurvey forums
array_filter() expects parameter 1 to be array, string given · Issue #47 · GeneaLabs/laravel-mixpanel · GitHub
PHP: array_filter() function - w3resource
array_filter() expects parameter 1 to be array, null given in Drupal\webform_mailchimp\Plugin\WebformHandler\WebformMailChimpHandler->postSave() [#3096797] | Drupal.org