How to redirect a wrong search on my wordpress website to the error 404 page?

Question

For example, my wordpress website is www.example.com. If I type example.com/abcdef or any other url that does not exist, it redirects to my custom 404 page without any issues.

However, when I search something, the url changes to www.example.com/?s=abcdef and it shows wordpress's default 'Nothing Found' page. Is there a way I can redirect a wrong search's to my custom 404 page or can I change wordpress 'Nothing found' page?

Thanks

Answer 1

A search shows the search template regardless of whether or not there are any results, which is either search.php or index.php if that template doesn't exist.

If you want to load an entirely different template, you can use the search_template filter. Assuming your theme's 404 template is 404.php:

function wpd_search_template( $template ) {
    if( ! have_posts() ) {
        $template = locate_template( array( '404.php' ) );
    }
    return $template;
}
add_filter( 'search_template', 'wpd_search_template' );