I'm trying to check the output of a variable in my functions.php file that runs after a new woocommerce order. The code will get the order time from a new order and store it in a variable for me to use elsewhere the code being:

$meeting_time = wc_get_order_item_meta($order_id, 'Time');

I've tried a few ways to print the information:

  • print_r
  • javascript popup box
  • writing to error log

but I can't seem to get any of these to work as my php knowledge isn't very good.

I want to be able to see the output of the variable to make sure it's returning what I want.

Is anyone able to assist me?

Please and thankyou.

  • Your print_r output won't be visible if $meeting_time is false or an empty string, you should surround it with something e.g. print_r( 'meetingtime: "'.$meeting_time.'"' ) – Tom J Nowell Dec 19 '16 at 0:59
  • Awesome, cheers Tom this makes perfect sense! I'm planning to run this when a new order is made at the 'woocommerce_new_order' hook which is during page load, is there anyway I can print the return of the variable somewhere? as the page goes to a new page after order and I can't seem to see it. – M.McI Dec 19 '16 at 1:11
  • error_log or a PHP debugger would do the trick, but you're not longer doing WP specific things at that point, you're doing general PHP things and would be better asking on Stack Overflow – Tom J Nowell Dec 19 '16 at 12:27

You can use var_dump() instead of print_r() - you get the type and the value of the variable and it will also work when your variable holds FALSE or NULL.

print_r( false ); # doesn't output anything
var_dump( false ); # output: bool(false)

print_r( NULL ); # doesn't output anything
var_dump( NULL ); # output: NULL

If you have arrays or objects to inspect, you could use a plugin like Kint Debugger to format the output into a more readable format.


wc_get_order_item_meta function requires an Order Item's ID, not the Order ID.

wc_get_order_item_meta($item_id, $key, $single );

Because all orders are stored as posts, you can get the post datetime from the order ID, and use that instead.

$order = get_post($orderID);
$order_time = $order->post_date;

then you can print that out using:

  • Hmm ok awesome info, thanks for the response! I should of mentioned that It's a bookable product the user can select a time and I was trying to get the time they have chosen from the meta data – M.McI Dec 19 '16 at 0:52
  • I tried to test the output by writing it to a file but nothing seemed to be printed, is this just because I wasn't using the function correctly? $meeting_time = wc_get_order_item_meta($order_id, 'Time'); $dump_meeting_time = var_dump($meeting_time); $file = 'wp-content/debuggo.php'; file_put_contents($file, $dump_meeting_time); – M.McI Dec 19 '16 at 0:57
  • Writing data to a file is something new, I would avoid introducing new problems while testing existing ones, and I would always check the return values of functions ( file_put_contents is very unlikely to succeed there, not unless your PHP file is in the root folder, which it almost certainly isn't ) – Tom J Nowell Dec 19 '16 at 0:58
  • Ok cool thanks for letting me know! I'm running this at a hook 'woocommerce_new_order' so I think when I print_r the output it happens during page load so I don't get to see the print_r, is there an easy way around this? – M.McI Dec 19 '16 at 1:03

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