_get_wcf_checkout_id_from_shortcode( string $content = '' )

function _get_wcf_checkout_id_from_shortcode( $content = '' ) {

	$checkout_id = 0;

	if ( ! empty( $content ) ) {

		$regex_pattern = get_shortcode_regex( array( 'cartflows_checkout' ) );

		preg_match( '/' . $regex_pattern . '/s', $content, $regex_matches );

		if ( ! empty( $regex_matches ) ) {

			if ( 'cartflows_checkout' == $regex_matches[2] ) {

				$attribure_str = str_replace( ' ', '&', trim( $regex_matches[3] ) );
				$attribure_str = str_replace( '"', '', $attribure_str );

				$attributes = wp_parse_args( $attribure_str );

				if ( isset( $attributes['id'] ) ) {
					$checkout_id = $attributes['id'];
				}
			}
		}
	}

	return $checkout_id;
}