WordPress at a glance
function is not described

wp_unique_id() WP 5.0.3

Gets unique ID.

This is a PHP implementation of Underscore's uniqueId method. A static variable contains an integer that is incremented with each call. This number is returned with the optional prefix. As such the returned value is not universally unique, but it is unique across the life of the PHP process.

No Hooks.

Return

String. Unique ID.

Usage

wp_unique_id( $prefix );
$prefix(string)
Prefix for the returned ID.

Changelog

Since 5.0.3 Introduced.

Code of wp_unique_id() WP 5.7.1

<?php
function wp_unique_id( $prefix = '' ) {
	static $id_counter = 0;
	return $prefix . (string) ++$id_counter;
}