somone explain this code?

[Monkuar]

if ($r['parent_id'] > 0)
            {
                $this->children[ $r['parent_id'] ][$r['id']] = $r;
            }
            else
            {
                $this->forums[ $r['id'] ] = $r;
            }

 

what is this code doing?

 

i don't get it how it uses the 2 variables in the " [ "  " ] " 's ? weird?

 

$r is a simple select * from a query..

 

i dont get the 2 variables with [] right next to each other?

[jcbones]

They are indexes in a multidimensional array.

PHP arrays-manual