private function isPrefixedKey($key)
    {
        if (strlen($key) > 1) {
            if (substr($key, 0, 1) == '_') {
                try {
                    intval(substr($key, 1, strlen($key) - 1));

                    return true;
                } catch (\Exception $e) {
                    return false;
                }
            }
        }
    }
private function isPrefixedKey($key)
    {
        if (strlen($key) > 1) {
            if (substr($key, 0, 1) == '_') {
                try {
                    intval(substr($key, 1, strlen($key) - 1));

                    return true;
                } catch (\Exception $e) {
                    return false;
                }
            }
        }
    }
private function isPrefixedKey ( $ key ) { if ( strlen ( $ key ) > 1 ) { if ( substr ( $ key , 0 , 1 ) == '_' ) { try { intval ( substr ( $ key , 1 , strlen ( $ key ) - 1 ) ) ; return true ; } catch ( \ Exception $ e ) { return false ; } } } }
Check if a string is in the proper format
to be a prefixed integral array key.

@param  string  $key
@return bool
Check if a string is in the proper format to be a prefixed integral array key .