A php function to implode an array full of arrays by a key in each of the arrays

implode_by_key.php

<?php

/**
 * Implodes an array full of arrays based on the passed key that is in each element of the array
 * by the passed delimiter
 *
 * implode_key(',', array(array('title'=>'jonathan'), array('title'=>'justin')), 'title')
 * // will return "jonathan,justin"
 *
 * @param string $delimiter
 * @param array $arrays
 * @param string $key
 * @return string
 */
function implode_by_key($delimiter, $arrays, $key)
{
    $new_array = array();
    foreach ($arrays as $array) {
        if (isset($array[$key]) == true) {
            $new_array[] = $array[$key];
        }
    }
    return implode($delimiter, $new_array);
}