<?php

use JMS\Serializer\SerializerBuilder;
use JMS\Serializer\SerializationContext;
use JMS\Serializer\Annotation\XmlKeyValuePairs;

$source = [
    'key' => 'value',
    'numbers' => [1,2,3,4],
    'sub' => [
        'key1' => 'val1',
        'key2' => 'val2',
    ],
];

$serializer = (new SerializerBuilder())
    ->build();

echo '<pre>' . $serializer->serialize($source, 'json') . '</pre>';

// xml need more configuration. This is just default
echo '<pre>' . htmlentities(
    $serializer->serialize($source, 'xml')
) . '</pre>';

{"key":"value","numbers":[1,2,3,4],"sub":{"key1":"val1","key2":"val2"}}

<?xml version="1.0" encoding="UTF-8"?>
<result>
  <entry><![CDATA[value]]></entry>
  <entry>
    <entry>1</entry>
    <entry>2</entry>
    <entry>3</entry>
    <entry>4</entry>
  </entry>
  <entry>
    <entry><![CDATA[val1]]></entry>
    <entry><![CDATA[val2]]></entry>
  </entry>
</result>

• Serialization to XML with JMS Serializer
• Create your own operator in Twig
• Export variables to a readable format

PHP 8.0, Laminas MVC 3.2, Symfony 5.2, Laravel 8.28, PHPUnit 9.5, Doctrine ORM 2.8