/**
  * createItem
  * --
  * @param Item $item
  * @param $sku
  * @param $description
  * @return ArrayOfItem|int|mixed|null
  */
 public function createItem(Item $item, $sku, $description)
 {
     if ($item != null) {
         // Instantiate a new ArrayOfItem
         try {
             // Set SKU & description of new item
             $item->setSKU($sku);
             $item->setDescription($description);
             // Set array of items, inc. above item.
             $aoItems = new ArrayOfItem();
             $aoItems->setItem([$item]);
             // return the new [items].
             return $aoItems;
         } catch (Exception $e) {
             // Something went wrong - error_log & return error message
             error_log($e->getMessage() . "-" . $e->getTraceAsString());
             return $e->getCode();
         }
     } else {
         return null;
     }
 }
<?php

require 'autoload.php';
require 'classes/autoload.php';
// Create a new ThreeCentralAPI Class
$a = new ThreeCentralAPI("{REDACTED}", "479", "23", "1", "Incapi", "Incapi");
// Retrieve the SoapClient
$b = $a->getClient();
// Retrieve the ExternalLoginInformation
$external_login_information = $a->getExtLoginData();
// Array of items
$aoItems = new ArrayOfItem();
// New item
$item = new Item($a->api_customer_id, 0.0, 1.0, 1.0, 1, InventoryMethod::LIFO, 0.99, 12.0, true, true, true, true, true, true, true, true, true, true, true, 5.0, MeasurementSystemType::USImperial, 25.0, 15.0, 10.0, 10.0, false, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 50.0, false, HazMatPackingGroup::aDefault, HazMatFlag::aDefault, 25.0, 0);
// set sku of that item
$item->setSKU("TEST1");
// set description
$item->setDescription("Testing API");
// add item to arr.
$aoItems->setItem([$item]);
// create order
$order = new Order(1);
// contact information
$contact_info = new ContactInfoExt(3);
// company name
$contact_info->setCompanyName("Some Company");
// contact information
$contact_info->setCustomerName("John Doe");
$contact_info->setDept("IT");
$contact_info->setPhoneNumber1("9547854455");
$contact_info->setName("Johnathon Doe");