WordPress at a glance
function is not described

is_main_blog() WP 3.0.0

Deprecated in 3.0.0. It is no longer supported and can be removed in future releases. Use is_main_site() instead.

Deprecated functionality to determin if the current site is the main site.

  • See: is_main_site()

No Hooks.

Return

Nothing (null).

Usage

is_main_blog();

Code of is main blog: wp-includes/ms-deprecated.php WP 5.2.2

<?php
function is_main_blog() {
	_deprecated_function( __FUNCTION__, '3.0.0', 'is_main_site()' );
	return is_main_site();
}