is_site_admin() WP 3.0.0

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

Determine if user is a site admin.

Plugins should use is_multisite() instead of checking if this function exists to determine if multisite is enabled.

This function must reside in a file included only if is_multisite() due to legacy function_exists() checks to determine if multisite is enabled.

No Hooks.

Return

Nothing (null).

Usage

is_site_admin( $user_login );

$user_login(string)

Username for the user to check.
Default: ''

Code of is site admin: wp-includes/ms-deprecated.php ^{WP 5.2.2}

<?php
function is_site_admin( $user_login = '' ) {
	_deprecated_function( __FUNCTION__, '3.0.0', 'is_super_admin()' );

	if ( empty( $user_login ) ) {
		$user_id = get_current_user_id();
		if ( !$user_id )
			return false;
	} else {
		$user = get_user_by( 'login', $user_login );
		if ( ! $user->exists() )
			return false;
		$user_id = $user->ID;
	}

	return is_super_admin( $user_id );
}