Hello everyone, I am trying to step by step build a small MQTT filter flow. I have my MQTT input all set up and can receive messages and I can "filter" using a function node with e.g. var msg = { payload: msg.payload.ENERGY['Total'] }; return msg; First issue :slight_smile: However, if a payloa…

Sorry, typing while on the road with a mobile does not let me indent while writing. So no worries, of course everything is indented correctly. It is just supposed to show what I am doing and where the ì` is coming from. Since I am declaring 5-6 arrays, I was hoping not to have to declare them as s…

[image] AleXSR700: So declaring first of course adds code when I am trying to minimize code. Do you mean minimise the amount of work that has to be done at run time, or minimise the amount of typing you have to do? If your original code had worked it would possibly make the generated code la…

The initial approach check if [0] exists, then [1], then [2] and each then with the full set of statements. So I changed to the i in length. Goal was to reduce lines of code (after having written them) and make it more "elegant" and efficient

[image] AleXSR700: make it more "elegant" Using msg.payload.ENERGY.Power.forEach() would be more elegant than a for loop. Also use push() to add elements to msg.Update and PowerDelta

Could you explain what the advantage of push() is? Did a quick syntax check and push always adds to the end. Is there any chance this will cause false order due to async or something? The order is relevant. I will check out forEach(). Need to see if it is just as easy :wink:

[image] AleXSR700: Is there any chance this will cause false order due to async or something? The order is relevant. That could only happen if you are doing the push inside an async process or if what you are pushing is an output from an async process.. Sorry, not checked the detailed flow so…

[image] AleXSR700: Could you explain what the advantage of push() is More elegant, no need to use i. Probably more efficient too. The order will always be the same as the order you go through the input array, provided you have not got any async code in there. Using forEach() you won't need …

Give it a try just now and although it works in principle, I have the problem that I am checking if a msg property needs updating and when it does not, I move to the next. So if item 1 does not need updating, it is not written to the array. If item 2 needs updating, it is written to the array as se…

[image] AleXSR700: I have the problem that I am checking if a msg property needs updating and when it does not, I move to the next. In that case you need to use i to write the output data. You can make the current index available in the callback function in forEach() by providing a second ar…

Yes, I had tried that and it works. Was just thinking if I can really do without the index, but I was not able to do so in my testing. :slight_smile:

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Beginner questions on IF expressions and wildcard usage in function node

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