src/Viserio/Component/Routing/Dispatcher/MiddlewareBasedDispatcher.php
protected static function flatten(array $array): array
    {
        $flattened = [];

        foreach ($array as $key => $value) {
            if (\is_array($value)) {
                $flattened = \array_merge($flattened, static::flatten($value));
            } else {
                $flattened[] = $value;
            }
        }

        return $flattened;
    }
protected static function flatten(array $array): array
    {
        $flattened = [];

        foreach ($array as $key => $value) {
            if (\is_array($value)) {
                $flattened = \array_merge($flattened, static::flatten($value));
            } else {
                $flattened[] = $value;
            }
        }

        return $flattened;
    }
Convert a multi-dimensional array into a single-dimensional array without keys.

@param array $array

@return array