Strip whitespace between HTML tags in wp_nav_menu()

gistfile1.aw

<?php

/* Modify the output of list items in the header navigation menu.
 *
 * Remove the whitespace between HTML tags. Required specifically for better
 * behavior when list items are inline-block in our main nav menu and need
 * the browsers to adhere to exact margins.
 *
 * NOTE: filter name changes depending on your menu - this one works for 'navigation_items'
*/
add_filter( 'wp_nav_menu_header-navigation_items', 'prefix_remove_menu_item_whitespace' );
function prefix_remove_menu_item_whitespace( $html_content ) {
	return preg_replace( '/>\s+</', '><', $html_content );
}

@slava-v, I get an error: "Missing argument 2 for prefix_remove_menu_item_whitespace()..."

Remove the second parameter and it works like a charm. Thanks.

I believe the wp_nav_menu_items filter can be used instead.

Now a better option is to add the argument 'item_spacing' => 'discard'