# Javascript switch in function node problem
**URL:** https://discourse.nodered.org/t/javascript-switch-in-function-node-problem/43820
**Category:** General
**Created:** [7 April 2021 14:35 UTC](https://discourse.nodered.org/t/javascript-switch-in-function-node-problem/43820 "2021-04-07T14:35:41Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@ricky.spanish6](https://discourse.nodered.org/u/ricky.spanish6)
#### Post date: [7 April 2021 14:35 UTC](https://discourse.nodered.org/t/javascript-switch-in-function-node-problem/43820/1 "2021-04-07T14:35:41Z")
Hi,
I was wondering if it was possible to compare values from different payloads in the same function. I keep getting an undefined error for my msg.payload[1]. Or if we can't, anybody would have a better idea?
Here is my flow:
```auto
[{"id":"fd617437.ba4bd8","type":"function","z":"14f8d12a.1216bf","name":"Switch","func":"host = msg.topic;\nbattery = msg.payload[0];\npower = msg.payload[1];\n\nswitch(host) {\n case \"mic1\" :\n if (battery === \"< REP 1 BATT_BARS 005 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (battery === \"< REP 1 BATT_BARS 004 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (battery === \"< REP 1 BATT_BARS 003 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (battery === \"< REP 1 BATT_BARS 002 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (battery === \"< REP 1 BATT_BARS 001 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (battery === \"< REP 1 BATT_BARS 000 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (battery === \"< REP 1 BATT_BARS 255 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (power === \"< REP 1 TX_RF_PWR UNKN >\") {\n msg.payload.battery = '';\n return [msg, null];\n }\n break;\n default:\n msg.payload = \"Unknown command\" ;\n return [null, null, msg];\n }\nreturn msg;","outputs":3,"noerr":0,"initialize":"","finalize":"","x":1670,"y":560,"wires":[["5a63a0d2.0192e","639ebaaf.06ff14"],[],["fa5eec2a.6b602"]]},{"id":"5a63a0d2.0192e","type":"debug","z":"14f8d12a.1216bf","name":"","active":false,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload.battery","targetType":"msg","statusVal":"payload","statusType":"auto","x":1920,"y":480,"wires":[]},{"id":"639ebaaf.06ff14","type":"debug","z":"14f8d12a.1216bf","name":"","active":false,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload.power","targetType":"msg","statusVal":"payload","statusType":"auto","x":1910,"y":540,"wires":[]},{"id":"fa5eec2a.6b602","type":"debug","z":"14f8d12a.1216bf","name":"","active":true,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload","targetType":"msg","statusVal":"payload","statusType":"auto","x":1890,"y":600,"wires":[]},{"id":"3add34e0.bab05c","type":"inject","z":"14f8d12a.1216bf","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"mic1","payload":"< REP 1 BATT_BARS 005 >","payloadType":"str","x":1270,"y":540,"wires":[["afe300da.e3e17"]]},{"id":"ddecd044.debda","type":"inject","z":"14f8d12a.1216bf","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":"0.5","topic":"mic1","payload":"< REP 1 TX_RF_PWR UNKN >","payloadType":"str","x":1260,"y":580,"wires":[["afe300da.e3e17"]]},{"id":"afe300da.e3e17","type":"join","z":"14f8d12a.1216bf","name":"","mode":"custom","build":"array","property":"payload","propertyType":"msg","key":"topic","joiner":"\\n","joinerType":"str","accumulate":false,"timeout":"1","count":"2","reduceRight":false,"reduceExp":"","reduceInit":"","reduceInitType":"","reduceFixup":"","x":1530,"y":560,"wires":[["fd617437.ba4bd8","4354a72f.531cd8"]]},{"id":"4354a72f.531cd8","type":"debug","z":"14f8d12a.1216bf","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":1670,"y":620,"wires":[]}]
```
---
### Author:  [@E1cid](https://discourse.nodered.org/u/E1cid)
#### Post date: [7 April 2021 15:11 UTC](https://discourse.nodered.org/t/javascript-switch-in-function-node-problem/43820/2 "2021-04-07T15:11:10Z")
Yes, the problem you have is you are joining as an array, but the messages can come in any order, so your array could be reversed. Try joining as an object
e.g.
```auto
[{"id":"ddecd044.debda","type":"inject","z":"af0e674c.7dafb8","name":"","props":[{"p":"payload"},{"p":"id","v":"power","vt":"str"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":"0.5","topic":"mic1","payload":"< REP 1 TX_RF_PWR UNKN >","payloadType":"str","x":210,"y":580,"wires":[["afe300da.e3e17"]]},{"id":"afe300da.e3e17","type":"join","z":"af0e674c.7dafb8","name":"","mode":"custom","build":"object","property":"payload","propertyType":"msg","key":"id","joiner":"\\n","joinerType":"str","accumulate":true,"timeout":"","count":"2","reduceRight":false,"reduceExp":"","reduceInit":"","reduceInitType":"","reduceFixup":"","x":440,"y":560,"wires":[["fd617437.ba4bd8","4354a72f.531cd8"]]},{"id":"3add34e0.bab05c","type":"inject","z":"af0e674c.7dafb8","name":"","props":[{"p":"payload"},{"p":"id","v":"battery","vt":"str"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"mic1","payload":"< REP 1 BATT_BARS 005 >","payloadType":"str","x":180,"y":540,"wires":[["afe300da.e3e17"]]},{"id":"fd617437.ba4bd8","type":"function","z":"af0e674c.7dafb8","name":"Switch","func":"host = msg.topic;\nbattery = msg.payload.battery;\npower = msg.payload.power;\n\nswitch(host) {\n case \"mic1\" :\n if (battery === \"< REP 1 BATT_BARS 005 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (battery === \"< REP 1 BATT_BARS 004 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (battery === \"< REP 1 BATT_BARS 003 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (battery === \"< REP 1 BATT_BARS 002 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (battery === \"< REP 1 BATT_BARS 001 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (battery === \"< REP 1 BATT_BARS 000 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (battery === \"< REP 1 BATT_BARS 255 >\") {\n msg.payload.battery = '';\n return [msg, null];\n } else if (power === \"< REP 1 TX_RF_PWR UNKN >\") {\n msg.payload.battery = '';\n return [msg, null];\n }\n break;\n default:\n msg.payload = \"Unknown command\" ;\n return [null, null, msg];\n }\nreturn msg;","outputs":3,"noerr":0,"initialize":"","finalize":"","x":580,"y":560,"wires":[["5a63a0d2.0192e","639ebaaf.06ff14"],[],["fa5eec2a.6b602"]]},{"id":"4354a72f.531cd8","type":"debug","z":"af0e674c.7dafb8","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":580,"y":620,"wires":[]},{"id":"5a63a0d2.0192e","type":"debug","z":"af0e674c.7dafb8","name":"","active":false,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload.battery","targetType":"msg","statusVal":"payload","statusType":"auto","x":830,"y":480,"wires":[]},{"id":"639ebaaf.06ff14","type":"debug","z":"af0e674c.7dafb8","name":"","active":false,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload.power","targetType":"msg","statusVal":"payload","statusType":"auto","x":820,"y":540,"wires":[]},{"id":"fa5eec2a.6b602","type":"debug","z":"af0e674c.7dafb8","name":"","active":true,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload","targetType":"msg","statusVal":"payload","statusType":"auto","x":800,"y":600,"wires":[]}]
```
---
### Author:  [@ricky.spanish6](https://discourse.nodered.org/u/ricky.spanish6)
#### Post date: [8 April 2021 13:51 UTC](https://discourse.nodered.org/t/javascript-switch-in-function-node-problem/43820/3 "2021-04-08T13:51:20Z")
That makes sense, I'll try that. Thanks!!
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [7 June 2021 13:51 UTC](https://discourse.nodered.org/t/javascript-switch-in-function-node-problem/43820/4 "2021-06-07T13:51:41Z")
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