- implode: documentation ( source)
- json_encode: documentation ( source)
<?php
$meta = [
'stationFrom' => 'Antwerpen',
'stationTo' => 'London',
'places' => [1, 3, 4],
];
$formattedMeta = [
'stationFrom' => 'Antwerpen',
'stationTo' => 'London',
'places' => function() use ($meta) {
return implode(',', $meta['places']);
}
];
$formattedMeta['places']();
echo json_encode($formattedMeta);