Get post ID outside of the loop

Question

I am trying to accomplish something somewhat simple I think. I have a menu item at the top of my page that I want to link to the latest post in a certain category. I just need to get the post ID of the latest post in the category so I can pass it to the menu. I want to do this outside of the loop and create a function in functions.php that will return the post ID. Does anyone have any suggestions on how to do this?

Answer 1

here is a function that does just that:

function get_lastest_post_of_category($cat){
    $args = array( 'posts_per_page' => 1, 'order'=> 'DESC', 'orderby' => 'date', 'category__in' => (array)$cat);
    $post_is = get_posts( $args );
    return $post_is[0]->ID;
}

Usage: say my category id is 22 then:

$last_post_ID = get_lastest_post_of_category(22);

you can also pass an array of categories to this function.