if post id matches these id’s then do this

I’m still a noob with php but I’m trying to display a different layout for my WordPress webpage for a single post id.

I thought it would have been simple but I’ve tried a quiet few variations of the code below. Including is_singular and without the $post etc. and I’ve ran out of inspiration. What can I do? What do I need to look for? Can anyone help me out?

<?php

if (is_single ($post="2578")) {
    get_template_part('partials/content', 'challenge');
} 
elseif (is_single ($post=""))  {
    get_template_part('partials/challenge/content', 'challenge-2');
    get_template_part('partials/challenge/content', 'categories');
    get_template_part('partials/challenge/content', 'snake-checklist');
    get_template_part('partials/challenge/content', 'timeline'); 
}?>

This looks almost correct. Let’s have a look at is_single():

Works for any post type, except attachments and pages…

So if the given ID isn’t that of a page or attachment post type then you can use the function as so:

if( is_single( 2578 ) ) {
    /* ... */
} else {
    /* ... */
}

Otherwise, if the ID is a page post type you can use is_page()

if( is_page( 2578 ) ) {
    /* ... */
}

Should the ID be that of an attachment page you may use is_attachment()

if( is_attachment( 2578 ) ) {
    /* ... */
}

Finally, if you’re unsure of the post type you could check against the global $post object, assuming it is correct:

global $post;
if( is_object( $post ) && 2578 == $post->ID ) {
    /* ... */
}