# Multiply 2 payloads after join node

**URL:** <https://discourse.nodered.org/t/multiply-2-payloads-after-join-node/49857>\
**Category:** General\
**Created:** [17 August 2021 20:50 UTC](https://discourse.nodered.org/t/multiply-2-payloads-after-join-node/49857 "2021-08-17T20:50:58Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![gjones84](https://avatars.discourse-cdn.com/v4/letter/g/7cd45c/32.png) [@gjones84](https://discourse.nodered.org/u/gjones84)\
**Post date:** [17 August 2021 20:50 UTC](https://discourse.nodered.org/t/multiply-2-payloads-after-join-node/49857/1 "2021-08-17T20:50:58Z")

</div>

Hi All,

Tried to find the answer for this. I can find how to sum 2 separate message payloads. But how do I multiply them together? See below. I want to multiply 10 by 20.

[{"id":"e1b07ecd.4ceac","type":"change","z":"f4e1027028f8a396","name":"Multiply(payload)","rules":[{"t":"set","p":"payload","pt":"msg","to":"$sum(payload)","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":810,"y":300,"wires":[["f9afb265.b11b7"]]}]

Thanks

Gareth

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<div class="post-metadata">

**Author:** ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)\
**Post date:** [17 August 2021 21:19 UTC](https://discourse.nodered.org/t/multiply-2-payloads-after-join-node/49857/2 "2021-08-17T21:19:49Z")

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Assuming you set the join node to key/value mode and the topics of the 2 messages are value1 & value2...

Add a function after the join

```auto
msg.payload = msg.payload.value1 * msg.payload.value2;
return msg;

```

See [this article in the cookbook](https://cookbook.nodered.org/basic/join-streams) for an example of how to join messages into one object.

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<div class="post-metadata">

**Author:** ![Gunner](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/gunner/32/43582_2.png) [@Gunner](https://discourse.nodered.org/u/Gunner)\
**Post date:** [17 August 2021 21:28 UTC](https://discourse.nodered.org/t/multiply-2-payloads-after-join-node/49857/3 "2021-08-17T21:28:26Z")

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I don't know where you are getting your msg.payloads... but I put this simple example together using...

![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/a/1/a11d1e8f1dbe2a9298dc2796e64df10a34a2fe81.png) ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/4/b/4b751b7560e1d8b0d7a2888578211765e2056f78.png)

![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/5/c/5c6246c930d6036f414d2637a8f5bb7ed6d7f483.png)

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<div class="post-metadata">

**Author:** ![E1cid](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/e1cid/32/77971_2.png) [@E1cid](https://discourse.nodered.org/u/E1cid)\
**Post date:** [17 August 2021 23:19 UTC](https://discourse.nodered.org/t/multiply-2-payloads-after-join-node/49857/4 "2021-08-17T23:19:05Z")

</div>

If you joined them as an array  
`payload[0]*payload[1]`

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<div class="post-metadata">

**Author:** ![gjones84](https://avatars.discourse-cdn.com/v4/letter/g/7cd45c/32.png) [@gjones84](https://discourse.nodered.org/u/gjones84)\
**Post date:** [18 August 2021 06:11 UTC](https://discourse.nodered.org/t/multiply-2-payloads-after-join-node/49857/6 "2021-08-18T06:11:06Z")

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Hi All,

Thank you for your replies. Like all things there is multiple ways of doing things. They all work for me. @E1cid seems to 'fit the bill'.

```auto
[{"id":"1dcd267e.52b91a","type":"join","z":"96864f49.e119a","name":"","mode":"custom","build":"array","property":"payload","propertyType":"msg","key":"payload","joiner":"\\n","joinerType":"str","accumulate":false,"timeout":"","count":"2","reduceRight":false,"reduceExp":"","reduceInit":"","reduceInitType":"","reduceFixup":"","x":520,"y":280,"wires":[["a1c21c0b.e5731","e1b07ecd.4ceac"]]},{"id":"3f6885c1.6d431a","type":"inject","z":"96864f49.e119a","name":"","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"10","payloadType":"num","x":180,"y":260,"wires":[["1dcd267e.52b91a"]]},{"id":"3d36ac8b.602294","type":"inject","z":"96864f49.e119a","name":"","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"2","payloadType":"num","x":180,"y":340,"wires":[["1dcd267e.52b91a"]]},{"id":"a1c21c0b.e5731","type":"debug","z":"96864f49.e119a","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":820,"y":400,"wires":[]},{"id":"280f8401.a0a70c","type":"debug","z":"96864f49.e119a","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":1100,"y":280,"wires":[]},{"id":"e1b07ecd.4ceac","type":"change","z":"96864f49.e119a","name":"Multiply(payload)","rules":[{"t":"set","p":"payload","pt":"msg","to":"payload[0]*payload[1]","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":810,"y":280,"wires":[["280f8401.a0a70c"]]}]

```

Cheers

Gareth

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [1 September 2021 06:12 UTC](https://discourse.nodered.org/t/multiply-2-payloads-after-join-node/49857/7 "2021-09-01T06:12:05Z")

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