PHP：将多维数组转换为字符串

Question

I am trying to convert a multidimensional array into a string.

Till now I have been able to convert a pipe delimited string into an array.

Such as:

group|key|value
group|key_second|value

Will render into the following array:

$x = array(
    'group' => array(
        'key' => 'value',
        'key_second' => 'value'
    ),
);

However, now I want it to be the other way around, where a multidimensional array is provided and I want to convert it to a pipe delimited string just like in the first code example.

Any ideas how to do this ?

---

PS: Please do note that the array can dynamically have any depth.

For example:

$x['group']['sub_group']['category']['key'] = 'value'

Translates to

group|sub_group|category|key|value

Answer 1

I have created my own function: This should have no problem handling even big arrays

function array_to_pipe($array, $delimeter = '|', $parents = array(), $recursive = false)
{
    $result = '';

    foreach ($array as $key => $value) {
        $group = $parents;
        array_push($group, $key);

        // check if value is an array
        if (is_array($value)) {
            if ($merge = array_to_pipe($value, $delimeter, $group, true)) {
                $result = $result . $merge;
            }
            continue;
        }

        // check if parent is defined
        if (!empty($parents)) {
            $result = $result . PHP_EOL . implode($delimeter, $group) . $delimeter . $value;
            continue;
        }

        $result = $result . PHP_EOL . $key . $delimeter . $value;
    }

    // somehow the function outputs a new line at the beginning, we fix that
    // by removing the first new line character
    if (!$recursive) {
        $result = substr($result, 1);
    }

    return $result;
}

Demo provided here http://ideone.com/j6nThF