Fix various compatibility issues with PHP 8

libs/ical/Property/ArrayValue.php

@@ -0,0 +1,41 @@
+<?php
+
+/*
+ * This file is part of the eluceo/iCal package.
+ *
+ * (c) Markus Poerschke <markus@eluceo.de>
+ *
+ * This source file is subject to the MIT license that is bundled
+ * with this source code in the file LICENSE.
+ */
+
+namespace Eluceo\iCal\Property;
+
+class ArrayValue implements ValueInterface
+{
+    /**
+     * The value.
+     *
+     * @var array
+     */
+    protected $values;
+
+    public function __construct(array $values)
+    {
+        $this->values = $values;
+    }
+
+    public function setValues(array $values)
+    {
+        $this->values = $values;
+
+        return $this;
+    }
+
+    public function getEscapedValue(): string
+    {
+        return implode(',', array_map(function (string $value): string {
+            return (new StringValue($value))->getEscapedValue();
+        }, $this->values));
+    }
+}