Compare numbers in switch node doesn't work

General
1

What's wrong comparing numbers with switch node? I don't get an error, so I think my code is correct:
grafik

The true comes from this function node, where it works:

let val = Date.now() / 1000 | 0;  // timestamp in sec

msg.payload = msg.payload === val ? true : false;

return msg;

My MQTT node uses JSON interpretation, to get a number. The flow:

grafik
grafik1014×354 28.2 KB

2

You will see the red box around your "number" this is because it is not a number, it needs to be evaluated first.

You can use jsonata to do calculations, although current time will change during the operation so you may not get a match to the payload anyway ?

What are you trying to do with the flow ?

3

If you want to check if msg.payload is true or false, then click the chevron next to "==" and select "is true" or "is false"
[edit] p.s. In your function code, when you divide your timestamp by 1000 you will end up with a float, you will need to round it. You also may want to compare if difference between timestamps(inseconds) is > or < than a certain period.

4

I don't really understand your answer. Why is it not a number? My code? In my function node, it will generate a number!?

Choosing JSONata will also result in a red box. Perhaps I have to change the code??

Problem could be the correct time, so I will need a function node anyway to unsharp the time.

I get a timestamp from another program on my RASPI via MQTT and this is my way to test, if the program sending the MQTT is alive.

5

numbers are for numbers only. It does NOT evaluate a forumla.

Your equation is not proper JSONata

6

The == is just comparing payload with what you type in - it doesn't do the calculation for you.

But if you do something like this, then it will. So injecting payload of 5 will pass to output 1

image

But as I said you would need to look at reducing the time stamp anyway to allow processing time :wink:

7

Ok, thanks I learned:
== is only for distinct numbers
JSONata is only for basic calculation (like adjust measurement)

8

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