- array_chunk: documentation ( source)
- preg_split: documentation ( source)
- preg_replace: documentation ( source)
- json_encode: documentation ( source)
<?php
$a = "position=1&x=0.203125&y=0.23125&position=2&x=0.8427083333333333&y=0.415625&position=3&x=0.5510416666666667&y=0.4375&";
$a = preg_replace("/&$/","",$a);
$array = array_chunk(preg_split("/&/",$a),3);
echo json_encode($array, JSON_PRETTY_PRINT);
?>