# Problem with number converting from mqtt retained messages

**URL:** <https://discourse.nodered.org/t/problem-with-number-converting-from-mqtt-retained-messages/21077>\
**Category:** General\
**Created:** [31 January 2020 10:33 UTC](https://discourse.nodered.org/t/problem-with-number-converting-from-mqtt-retained-messages/21077 "2020-01-31T10:33:54Z")\
**Posts on this page:** 1\
**Showing post:** 20

<div class="post-metadata">

**Author:** ![afelix](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/afelix/32/9743_2.png) [@afelix](https://discourse.nodered.org/u/afelix)\
**Post date:** [4 February 2020 17:02 UTC](https://discourse.nodered.org/t/problem-with-number-converting-from-mqtt-retained-messages/21077/20 "2020-02-04T17:02:24Z")

</div>

The reason you’re seeing these errors is because your properties contain slashes which are interpreted as divisor rather than part of the name. I saw this same issue explained to someone else a couple days ago, let me dig up the post for you. You can follow the instructions there to get rid of this error, then continue with the next part: following the instructions of those posting above me.

> [@How to create function on rpi node red with two gpio - if gpio1 == 1 && gpio2 ==0 then gpio3=1](https://discourse.nodered.org/t/how-to-create-function-on-rpi-node-red-with-two-gpio-if-gpio1-1-gpio2-0-then-gpio3-1/20406/27):
>
> Ah the joy of javascript.... your combined payloads look like this [image] all good so far Then your function does this if (msg.payload.pi/35 == 1 && msg.payload.pi/37 == 1) { which is a natural thing to do... but javascript doesn't like / in property names so it will be treating it like a divide :-)... so instead you need to do if (msg.payload["pi/35"] == 1 && msg.payload["pi/37"] == 1) {

---

_[View the full topic](https://discourse.nodered.org/t/problem-with-number-converting-from-mqtt-retained-messages/21077)._