Select DISTINCT values of a fields in a pages selector

[abmcr]

I need retrieve a list DISTINCT of values of a field (city) in a selector.

now i have create a foreach Cycle for get the pages 

$arr=array();
$p=$pages->find(...);
foreach($p as $el){
  $arr[]=$el->city;
}
//now unique...

But there is a most efficient way?

thank in advance

[abdus]

Not necessarily a faster way (I haven't tested its performance), but you can do

$uniques = array_unique($p->explode('city')):

 

[dragan]

maybe you could use this? http://cheatsheet.processwire.com/pagearray-wirearray/getting-items/a-unique/

[abdus]

That wouldn't work here though. That method filters out the duplicate elements, not the elements that have the same field value.