Removing posts from search results

I want to remove all posts from search results and the following was a little vague:

http://www.wpbeginner.com/wp-tutorials/how-to-exclude-pages-from-wordpress-search-results/comment-page-1/#comment-179451

Is the following code that I added correct:
function SearchFilter($query) {
if ($query->is_search) {
$query->set(‘post_type’, ‘pages’);
}
return $query;
}

add_filter(‘pre_get_pages’,’SearchFilter’);