# Beginner questions on IF expressions and wildcard usage in function node

**URL:** https://discourse.nodered.org/t/beginner-questions-on-if-expressions-and-wildcard-usage-in-function-node/80999
**Category:** General
**Created:** [3 September 2023 11:43 UTC](https://discourse.nodered.org/t/beginner-questions-on-if-expressions-and-wildcard-usage-in-function-node/80999 "2023-09-03T11:43:38Z")
**Posts on this page:** 1
**Showing post:** 30

<div class="post-metadata">

### Author: ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [3 September 2023 15:18 UTC](https://discourse.nodered.org/t/beginner-questions-on-if-expressions-and-wildcard-usage-in-function-node/80999/30 "2023-09-03T15:18:19Z")

</div>

Or using filter

```auto
[{"id":"3f53197d243846c3","type":"inject","z":"bdd7be38.d3b55","name":"With ATC","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"{\"mac\":\"a4c1380d5c0c\",\"Temperature\":21.6,\"Humidity\":64.7,\"DewPoint\":14.7,\"Btn\":0,\"Battery\":37,\"ATC1\":\"this is the value of ATC1\",\"RSSI\":-64}","payloadType":"json","x":700,"y":140,"wires":[["853adc83d89cddaa"]]},{"id":"3586ec0a6edd8630","type":"inject","z":"bdd7be38.d3b55","name":"No ATC","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"{\"mac\":\"a4c1380d5c0c\",\"Temperature\":21.6,\"Humidity\":64.7,\"DewPoint\":14.7,\"Btn\":0,\"Battery\":37,\"RSSI\":-64}","payloadType":"json","x":690,"y":180,"wires":[["853adc83d89cddaa"]]},{"id":"aaaaf1995c5b6682","type":"inject","z":"bdd7be38.d3b55","name":"Multiple ATC*","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"{\"mac\":\"a4c1380d5c0c\",\"Temperature\":21.6,\"Humidity\":64.7,\"DewPoint\":14.7,\"Btn\":0,\"Battery\":37,\"ATC1\":\"this is the value of ATC1\",\"ATC2\":\"this is the value of ATC2\",\"RSSI\":-64}","payloadType":"json","x":710,"y":220,"wires":[["853adc83d89cddaa"]]},{"id":"853adc83d89cddaa","type":"function","z":"bdd7be38.d3b55","name":"filter()","func":"// get an array of all keys starting with ATC\nconst matchingKeys = Object.keys(msg.payload).filter((element) => element.startsWith(\"ATC\"))\n// send them\nmatchingKeys.forEach((element) => node.send({payload: msg.payload[element]}))","outputs":1,"timeout":0,"noerr":0,"initialize":"","finalize":"","libs":[],"x":870,"y":200,"wires":[["68be1dc221018baa"]]},{"id":"68be1dc221018baa","type":"debug","z":"bdd7be38.d3b55","name":"debug 99","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":1020,"y":160,"wires":[]}]

```

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