loops and strings

Traffic Jam

#!/usr/bin/php
<?php
$response = "PNBX|%O=87%N=10%S=OK|%XLL=39.988773,-75.413552%XSN=Bus Center Rd%XSN=%DIST=m73|%XLL=39.990304,-75.410596%XSN=%XSN=Bus Center Rd%DIST=m239|%XLL=39.990411,-75.408906%XSN=Medical Dr%XSN=%DIST=m377|%XLL=39.985864,-75.412136%XSN=College Ave%XSN=W Chester Pike\:RN/PA-3///USA3%DIST=m395|%XLL=39.986115,-75.410542%XSN=Ellis Ave\:AX/Ellis Rd%XSN=W Chester Pike\:RN/PA-3///USA3%DIST=m419|%XLL=39.985758,-75.414813%XSN=%XSN=W Chester Pike\:RN/PA-3///USA3%DIST=m423|%XLL=39.986007,-75.410518%XSN=Ellis Ave\:AX/Ellis Rd%XSN=W Chester Pike\:RN/PA-3///USA3%DIST=m431|%XLL=39.985630,-75.414794%XSN=%XSN=W Chester Pike\:RN/PA-3///USA3%DIST=m436|%XLL=39.991259,-75.417594%XSN=Rockwood Farm Rd%XSN=Goshen Rd%DIST=m437|%XLL=39.985443,-75.412090%XSN=College Ave%XSN=Hickory Ln%DIST=m442||";

$str = strstr($response, '%XLL');

$arr = explode('|', $str);

$res = [];

foreach ($arr as $v) {
    $matches = [];

    preg_match_all('/%(\w+)=([^%]*)/', $v, $matches);

    $keys = $matches[1];

    if (!count($keys)) {
        continue;
    }

    $combined = [];

    foreach ($matches[2] as $index => $val) {
        if ($val && isset($combined[$keys[$index]])) {
            $combined[$keys[$index]] .= '|' . $val;
        }
        else if ($val) {
            $combined[$keys[$index]] = $val;
        }
    }

    $res []= $combined;
}

print_r($res);

?>