WordPress at a glance
function is not described

WP_User::get_site_id() public WP 4.9.0

Gets the ID of the site for which the user's capabilities are currently initialized.

{} It's a method of the class: WP_User{}

No Hooks.

Return

Int. Site ID.

Usage

$WP_User = new WP_User();
$WP_User->get_site_id();

Changelog

Since 4.9.0 Introduced.

Code of WP_User::get_site_id() WP 5.7.1

<?php
public function get_site_id() {
	return $this->site_id;
}