WP_Query::is_preview │ public │ WP 3.1.0

Determines whether the query is for a post or page preview.

Method of the class: WP_Query{}

No Hooks.

Returns

true|false. Whether the query is for a post or page preview.

Usage

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

Changelog

Since 3.1.0 Introduced.

WP_Query::is_preview() code WP 6.9

wp-includes/class-wp-query.php 
public function is_preview() {
	return (bool) $this->is_preview;
}