- htmlspecialchars: documentation ( source)
<?php
$KalenderUser = [
0 => ['vorname' => 'Ferdl', 'name' => 'Feuerstein'],
1 => ['vorname' => 'Hans', 'name' => 'Hohlbein']
];
$output = "";
$cnt=count($KalenderUser);
for($i=0; $i<$cnt; ++$i)
{
$output .= htmlspecialchars($KalenderUser[$i]['vorname'] . " " . $KalenderUser[$i]['name']);
if($i < $cnt-1) {
$output .= ", ";
}
}
echo $output;