Getting Max Value from an array - php

Question

Hi I am trying to use an api from postcodeanywhere that calcuates the total travel time and distance for a particular journey, and I have got it working using the following code:
//Build URL Request
$url = "http://services.postcodeanywhere.co.uk/DistancesAndDirections/Interactive/Directions/v2.00/xmla.ws?";
$url .= "&Key=" . urlencode($Key);
$url .= "&Start=" . urlencode($Start);
$url .= "&Finish=" . urlencode($Finish);
$url .= "&DistanceType=" . urlencode($DistanceType);
//Make the request to Postcode Anywhere and parse the XML returned
$file = simplexml_load_file($url);
//Check for an error, if there is one then throw an exception
if ($file->Columns->Column->attributes()->Name == "Error")
{
throw new Exception("[ID] " . $file->Rows->Row->attributes()->Error . " [DESCRIPTION] " . $file->Rows->Row->attributes()->Description . " [CAUSE] " . $file->Rows->Row->attributes()->Cause . " [RESOLUTION] " . $file->Rows->Row->attributes()->Resolution);
}
//Copy the data
if ( !empty($file->Rows) )
{
foreach ($file->Rows->Row as $item)
{
$Data[] = array('SegmentNumber'=>$item->attributes()->SegmentNumber,'StepNumber'=>$item->attributes()->StepNumber,'Action'=>$item->attributes()->Action,'Description'=>$item->attributes()->Description,'Road'=>$item->attributes()->Road,'StepTime'=>$item->attributes()->StepTime,'StepDistance'=>$item->attributes()->StepDistance,'TotalTime'=>$item->attributes()->TotalTime,'TotalDistance'=>$item->attributes()->TotalDistance);
$TotalDistance = ($item["TotalDistance"] * 0.000621371192);
echo $TotalDistance."<br>";
Which results in the following screenshot
The problem I am having is that the echo shows that it is displaying distance for each journey step, whereas I just want the max value.
I have tried $TotalDistance = max($item["TotalDistance"]). only to get the following error:
max(): When only one parameter is given, it must be an array
Any help would be appreciated.

Answer 1

You can get the max value:
$value = max($array);

Answer 2

What you could do is put the total distance into an array first, then grab the max. Like this:
$distance_array = new array();
foreach ($file->Rows->Row as $item)
{
$Data[] = array('SegmentNumber'=>$item->attributes()->SegmentNumber,'StepNumber'=>$item->attributes()->StepNumber,'Action'=>$item->attributes()->Action,'Description'=>$item->attributes()->Description,'Road'=>$item->attributes()->Road,'StepTime'=>$item->attributes()->StepTime,'StepDistance'=>$item->attributes()->StepDistance,'TotalTime'=>$item->attributes()->TotalTime,'TotalDistance'=>$item->attributes()->TotalDistance);
$TotalDistance = ($item["TotalDistance"] * 0.000621371192);
array_push($distance_array, $TotalDistance); //add the distance to an array
}
echo max($distance_array);
http://php.net/manual/en/function.array-push.php
http://php.net/manual/en/function.max.php