get_site_url( int|null $blog_id = null, string $path = '', string|null $scheme = null ): string

3534function get_site_url( $blog_id = null, $path = '', $scheme = null ) {3535	if ( empty( $blog_id ) || ! is_multisite() ) {3536		$url = get_option( 'siteurl' );3537	} else {3538		switch_to_blog( $blog_id );3539		$url = get_option( 'siteurl' );3540		restore_current_blog();3541	}3542 3543	$url = set_url_scheme( $url, $scheme );3544 3545	if ( $path && is_string( $path ) ) {3546		$url .= '/' . ltrim( $path, '/' );3547	}3548 3549	/**3550	 * Filters the site URL.3551	 *3552	 * @since 2.7.03553	 *3554	 * @param string      $url     The complete site URL including scheme and path.3555	 * @param string      $path    Path relative to the site URL. Blank string if no path is specified.3556	 * @param string|null $scheme  Scheme to give the site URL context. Accepts 'http', 'https', 'login',3557	 *                             'login_post', 'admin', 'relative' or null.3558	 * @param int|null    $blog_id Site ID, or null for the current site.3559	 */3560	return apply_filters( 'site_url', $url, $path, $scheme, $blog_id );3561}