PHP代码输出三级导航

Question

I'm working on an ExpressionEngine site and I have a loop outputting a sorted list. What I would like to do is output a list three levels deep using PHP.

/apples/black/rotten
/apples/green/cortland
/apples/green/cortland
/apples/red/granny
/apples/red/granny
/bananas/green/bad
/bananas/green/bad
/bananas/yellow/good
/bananas/yellow/good
/oranges/orange/tasty
/oranges/yellow/small
/oranges/yellow/small

What is the best method for converting this to a nested list?

Obviously this is a made up list for illustration. I've been trying to figure this out for a couple of days now and have had no luck. Is recursion an option.

Answer 1

$arr = array();
foreach (file(..., FILE_IGNORE_NEW_LINES) as $line)
{
    $tmp = explode("/", substr($line, 1));
    for ($i=0; $i<=2; $i++)
    {
        switch ($i)
        {
            case 0:
                if ( ! isset($arr[$tmp[0]]))
                {
                    $arr[$tmp[0]] = array();
                }
                break;
            case 1:
                if ( ! isset($arr[$tmp[1]]))
                {
                    $arr[$tmp[0]][$tmp[1]] = $tmp[2];
                }
                break;
        }
    }
}

Use of file is assuming the expression results is stored into a text file,
you can directly iterate if is already in array