WordPress at a glance
function is not described

wp_clear_auth_cookie() WP 2.5.0

Removes all of the cookies associated with authentication.

This is a pluggable function, and it can be replaced from plugin. It means that this function is defined (works) only after all plugins are connected (included), but before this moment the function has not yet been defined... Therefore, you cannot call this and all functions depended on this function directly from a plugin code. It must be called via hook plugins_loaded or later, for example on hook init.

Function replacement (override) — in a plugin you can create a function with the same name, then it will replace this function.

Hooks in function
Return

Nothing (null).

Usage

wp_clear_auth_cookie();

Code of wp clear auth cookie: wp-includes/pluggable.php VER 5.0.3

<?php
function wp_clear_auth_cookie() {
	/**
	 * Fires just before the authentication cookies are cleared.
	 *
	 * @since 2.7.0
	 */
	do_action( 'clear_auth_cookie' );

	/** This filter is documented in wp-includes/pluggable.php */
	if ( ! apply_filters( 'send_auth_cookies', true ) ) {
		return;
	}

	// Auth cookies
	setcookie( AUTH_COOKIE,        ' ', time() - YEAR_IN_SECONDS, ADMIN_COOKIE_PATH,   COOKIE_DOMAIN );
	setcookie( SECURE_AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, ADMIN_COOKIE_PATH,   COOKIE_DOMAIN );
	setcookie( AUTH_COOKIE,        ' ', time() - YEAR_IN_SECONDS, PLUGINS_COOKIE_PATH, COOKIE_DOMAIN );
	setcookie( SECURE_AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, PLUGINS_COOKIE_PATH, COOKIE_DOMAIN );
	setcookie( LOGGED_IN_COOKIE,   ' ', time() - YEAR_IN_SECONDS, COOKIEPATH,          COOKIE_DOMAIN );
	setcookie( LOGGED_IN_COOKIE,   ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH,      COOKIE_DOMAIN );

	// Settings cookies
	setcookie( 'wp-settings-' . get_current_user_id(),      ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH );
	setcookie( 'wp-settings-time-' . get_current_user_id(), ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH );

	// Old cookies
	setcookie( AUTH_COOKIE,        ' ', time() - YEAR_IN_SECONDS, COOKIEPATH,     COOKIE_DOMAIN );
	setcookie( AUTH_COOKIE,        ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );
	setcookie( SECURE_AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH,     COOKIE_DOMAIN );
	setcookie( SECURE_AUTH_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );

	// Even older cookies
	setcookie( USER_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH,     COOKIE_DOMAIN );
	setcookie( PASS_COOKIE, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH,     COOKIE_DOMAIN );
	setcookie( USER_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );
	setcookie( PASS_COOKIE, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );

	// Post password cookie
	setcookie( 'wp-postpass_' . COOKIEHASH, ' ', time() - YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
}