Question

A novice array question…

Given an array with this structure:

$post_dates Array [1]   
    [0...0] 
        2640    Array [2]   
            [0...1] 
                _id 2640    
                date_posted MongoDate

How would I access the date_posted element when the 1st level key is not always the same?
I thought I could just have this:

$post_dates[0]['date_posted']

But that’s giving me an ‘Undefined Offset’ message.
I’ve also tried

$post_dates[0][1]

but that gives the same message.

This is the code block where I am getting the error:

foreach($posts as $post){

        $post_dates = iterator_to_array($posts_coll->find(array("topic_id"=>$post['_id']), array("date_posted"=>true)));

        if (empty($post_dates)){ // No replies, therefore last post date = date_posted
            //$replies = 0;
            $lastPost = date("d-M-Y h:i:s", $post['date_posted']->sec);
            echo "condition 1, last post date: " . $lastPost . "<br>";
        }
        elseif (count($post_dates) == 1) { // One reply, therefore last post date = $post_dates[date_posted]            
            //$lastPost = date("d-M-Y h:i:s", $post_dates[0][1]->sec);
            echo "condition 2, last post date: " . $lastPost . "<br>";
            var_dump($post_dates[0]['_id']);
        }
        else {
            // code to determine max date_posted if there is more than one reply
        }

}

Answer 1

If you don’t know any of the keys in the chain $array["known"]["also_known"][???]["date_posted"], you’ll have to iterate the array in order to figure out which has the date_posted you need.