Custom post type as an archive

https://codex.www.ads-software.com/Function_Reference/query_posts#Post_.26_Page_Parameters

I already use custom query_posts to retrieve my stuff. The question is more : how do I know I have to retrieve all the articles of the custom type “news” ?
Is there any way for me to do something like

<?php if ($_GET["post_type"] == "news") {
// do something
} ?>

(I tried the code above, it doesn’t work…)

Thanks !

Try this. It works for me.

<?php if ( get_post_type() == 'news' ) {
    //your output
}; ?>

FYI, I created a plug-in that adds fully baked “archives” support to custom post types.

https://www.cmurrayconsulting.com/software/wordpress-custom-post-type-archives/