Add and autoload the array helper

application/config/autoload.php

@@ -66,6 +66,7 @@ $autoload['libraries'] = ['database', 'session'];
 */
 
 $autoload['helper'] = [
+    'array',
     'asset',
     'config',
     'debug',

application/helpers/array_helper.php

@@ -0,0 +1,78 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Open Source Web Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) 2013 - 2020, Alex Tselegidis
+ * @license     http://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        http://easyappointments.org
+ * @since       v1.4.0
+ * ---------------------------------------------------------------------------- */
+
+if ( ! function_exists('is_assoc'))
+{
+    /**
+     * Check if an array is an associative array.
+     *
+     * @param array $array
+     *
+     * @return bool
+     */
+    function is_assoc(array $array): bool
+    {
+        if (empty($array))
+        {
+            return FALSE;
+        }
+
+        return array_keys($array) !== range(0, count($array) - 1);
+    }
+}
+
+if ( ! function_exists('array_find'))
+{
+    /**
+     * Find the first array element based on the provided function.
+     *
+     * @param array $array
+     * @param callable $callback
+     *
+     * @return mixed
+     */
+    function array_find(array $array, callable $callback): mixed
+    {
+        if (empty($array))
+        {
+            return NULL;
+        }
+
+        if ( ! is_callable($callback))
+        {
+            throw new InvalidArgumentException('No filter function provided.');
+        }
+
+        return array_filter($array, $callback)[0] ?? NULL;
+
+    }
+}
+
+if ( ! function_exists('array_fields'))
+{
+    /**
+     * Keep only the provided fields of an array.
+     *
+     * @param array $array
+     * @param array $fields
+     *
+     * @return array
+     */
+    function array_fields(array $array, array $fields): array
+    {
+        return array_filter($array, function ($field) use ($fields) {
+            return in_array($field, $fields);
+        }, ARRAY_FILTER_USE_KEY);
+    }
+}
+