wp-includes/functions.php:6604Gets the main network ID.
intOne hook fires while get_main_network_id() runs, in this order:
function get_main_network_id() { if ( ! is_multisite() ) { return 1; } $current_network = get_network(); if ( defined( 'PRIMARY_NETWORK_ID' ) ) { $main_network_id = PRIMARY_NETWORK_ID; } elseif ( isset( $current_network->id ) && 1 === (int) $current_network->id ) { // If the current network has an ID of 1, assume it is the main network. $main_network_id = 1; } else { $_networks = get_networks( array( 'fields' => 'ids', 'number' => 1, ) ); $main_network_id = array_shift( $_networks ); } /** * Filters the main network ID. * * @since 4.3.0 * * @param int $main_network_id The ID of the main network. */ return (int) apply_filters( 'get_main_network_id', $main_network_id );}Introduced in 4.3.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.