WordPress at a glance
function is not described

_get_widget_id_base() WP 2.8.0

Retrieves the widget ID base value.

No Hooks.

Return

String. Widget ID base.

Usage

_get_widget_id_base( $id );
$id(string) (required)
Widget ID.

Code of get widget id base: wp-includes/widgets.php VER 5.1.1

<?php
function _get_widget_id_base( $id ) {
	return preg_replace( '/-[0-9]+$/', '', $id );
}