WordPress at a glance
function is not described

WP_Query::is_404() public WP 3.1.0

Is the query a 404 (returns no results)?

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

No Hooks.

Return

true/false. Whether the query is a 404 error.

Usage

global $wp_query;
$wp_query->is_404();

Changelog

Since 3.1.0 Introduced.

Code of WP_Query::is_404() WP 5.5.2

<?php
public function is_404() {
	return (bool) $this->is_404;
}