is_main_network( int $network_id = null ): bool
- Since
- 3.7.0
- Source
wp-includes/functions.php:6454
Compatibility
- WordPress
- since 3.7.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Parameters
$network_idintoptional- Network ID to test. Defaults to current network.Default:
null
Return value
bool- True if $network_id is the main network, or if not running Multisite.
Performance profile
How much work a call to is_main_network() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Trivial
- Scaling
- Constant
- Instructions
- 5–15
- Plugin surface
- None
- Called by
- 4
Touches nothing outside its own arguments.
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 16.
Nothing here hands control to plugin code.
4 places in core call this, so the cost is paid more often than your own code shows.
What it touches
- hookthird-party callbacks
apply_filters()one call below is_main_network()
What one call costs · 3 distinct outcomes
One number would be a lie: the work depends on which branch runs. These are every distinct cost is_main_network() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
!is_multisite() | 5 | is_multisite() |
is_multisite() && $network_id !== null | 12 | is_multisite(), get_main_network_id() |
is_multisite() && $network_id === null | 15 | is_multisite(), get_current_network_id(), get_main_network_id() |
Across PHP versions
Compiles the same on PHP 7.4, 8.1, 8.2, 8.3, 8.4, 8.5 and 8.6-dev: 16 instructions, 5–15 executed per call, 2 branches. The work does not change between versions.
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Uses · 3
- is_multisite()Determines whether Multisite is enabled.
- get_current_network_id()Retrieves the current network ID.
- get_main_network_id()Gets the main network ID.
Used by · 4
- WP_Automatic_Updater::run()Kicks off the background update process, looping through all pending updates.
- _wp_upload_dir()A non-filtered, non-cached version of wp_upload_dir() that doesn't check the path.
- delete_expired_transients()Deletes all expired transients.
- wp_should_upgrade_global_tables()Determine if global tables should be upgraded.
Source code
function is_main_network( $network_id = null ) { if ( ! is_multisite() ) { return true; } if ( null === $network_id ) { $network_id = get_current_network_id(); } $network_id = (int) $network_id; return ( get_main_network_id() === $network_id );}Changelog
Introduced in 3.7.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 6.9.7 tag, from
src/wp-includes/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.