WP_Customize_Nav_Menu_Section::json()

Source

File: wp-includes/customize/class-wp-customize-nav-menu-section.php

public function json() {
		$exported            = parent::json();
		$exported['menu_id'] = (int) preg_replace( '/^nav_menu\[(-?\d+)\]/', '$1', $this->id );

		return $exported;
	}