Multiple is_page() in page.php

Question

I'm trying to add multiple page IDs into an if else statement. This is my code so far:

if ( is_page(ID) || is_page(ID) ) { 
    get_header('header_alt'); 
} else { 
    get_header(); 
}

I tried a few other solutions found on google, yet it always only works on the initial page after clearing the cache.

Answer 1

You can pass an array of IDs to is_page instead of using multiple is_page:

if( is_page( array( 11, 22, 33, 44 ) ) ) {
    // Your code
}

Also, if you are using it in a loop, you should consider this note:

Due to certain global variables being overwritten during The Loop, is_page() will not work. In order to call it after The Loop, you must call wp_reset_query() first.

Answer 2

To add to Jack Johansson's answer, this also works for page slugs.
For example:

if( is_page( array('news', 'work', 'about', 'contact' ) ) ) {
// Your code
}