# Linking two or more conditions in a function node - syntax?
**URL:** https://discourse.nodered.org/t/linking-two-or-more-conditions-in-a-function-node-syntax/81997
**Category:** General
**Created:** [13 October 2023 10:19 UTC](https://discourse.nodered.org/t/linking-two-or-more-conditions-in-a-function-node-syntax/81997 "2023-10-13T10:19:26Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@pinie\_pinie](https://discourse.nodered.org/u/pinie_pinie)
#### Post date: [13 October 2023 10:19 UTC](https://discourse.nodered.org/t/linking-two-or-more-conditions-in-a-function-node-syntax/81997/1 "2023-10-13T10:19:26Z")
Hello,
I need the syntax for a function node to compare at least 2 conditions at the input and then generate a result accordingly.
e.g. At the input the values 20 and 40 come from 2 nodes.
Now the connection: If payload 1 = 20 and payload 2 \< 40 then
output "Error".
or:
If payload 1 \>20 and payload 2 \<40 then
output "Correct", etc.
Since I don't have any knowledge, I can't understand the required syntax in a function node.
Can anyone help?
---
### Author:  [@marcus-j-davies](https://discourse.nodered.org/u/marcus-j-davies)
#### Post date: [13 October 2023 10:29 UTC](https://discourse.nodered.org/t/linking-two-or-more-conditions-in-a-function-node-syntax/81997/2 "2023-10-13T10:29:34Z")
Hi @pinie_pinie
There are a few ways to accomplish this.
One that springs to my mind is using the `join` node.
you can set it to output a key:value pair after n payloads have been received.
The key will be the `topic` of each incoming payload.
```auto
[{"id":"d18ef770d90dd6f9","type":"inject","z":"5f4f6ef5a6e88063","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"M1","payload":"","payloadType":"date","x":2110,"y":215,"wires":[["11566532fd5b14da"]]},{"id":"fc46771fd736960d","type":"inject","z":"5f4f6ef5a6e88063","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"M2","payload":"","payloadType":"date","x":2115,"y":255,"wires":[["11566532fd5b14da"]]},{"id":"11566532fd5b14da","type":"join","z":"5f4f6ef5a6e88063","name":"","mode":"custom","build":"object","property":"payload","propertyType":"msg","key":"topic","joiner":"\\n","joinerType":"str","accumulate":false,"timeout":"","count":"2","reduceRight":false,"reduceExp":"","reduceInit":"","reduceInitType":"","reduceFixup":"","x":2325,"y":240,"wires":[["56aecb562d938a0e"]]},{"id":"56aecb562d938a0e","type":"debug","z":"5f4f6ef5a6e88063","name":"debug 2","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":2535,"y":240,"wires":[]}]
```
In a `function` node after the `join` you can then do.
```auto
if(payload.M1 === 20 && payload.M2 < 40){
// do stuff
}
```
---
### Author:  [@pinie\_pinie](https://discourse.nodered.org/u/pinie_pinie)
#### Post date: [13 October 2023 11:00 UTC](https://discourse.nodered.org/t/linking-two-or-more-conditions-in-a-function-node-syntax/81997/3 "2023-10-13T11:00:18Z")
Hello,
Thanks, I understood the first steps but how do you get the desired result?
[flows(1).json](https://discourse.nodered.org/uploads/short-url/dNyC9yeQFSB5XmoRN4XN9YPt5KI.json) (1.4 KB)
---
### Author:  [@marcus-j-davies](https://discourse.nodered.org/u/marcus-j-davies)
#### Post date: [13 October 2023 11:35 UTC](https://discourse.nodered.org/t/linking-two-or-more-conditions-in-a-function-node-syntax/81997/4 "2023-10-13T11:35:31Z")
Hi @pinie_pinie
Sorry - I missed `msg` in my example.
```auto
if(msg.payload.M1 === 20 && msg.payload.M2 < 40){
msg.payload = "Error"
} else {
msg.payload = "OK"
}
return msg;
```
`msg` is the entry point into the message flowing through everything
---
### Author:  [@pinie\_pinie](https://discourse.nodered.org/u/pinie_pinie)
#### Post date: [13 October 2023 12:58 UTC](https://discourse.nodered.org/t/linking-two-or-more-conditions-in-a-function-node-syntax/81997/5 "2023-10-13T12:58:55Z")
Hello,
that's exactly how I wanted it. I tested it with three conditions and it worked. The “Join” node is the crucial point.
Many thanks for the quick response.
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [12 December 2023 12:59 UTC](https://discourse.nodered.org/t/linking-two-or-more-conditions-in-a-function-node-syntax/81997/6 "2023-12-12T12:59:09Z")
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