If expression on multiple items behaves strange

[Cenitor]

Describe the problem/error/question

I want to check incoming items with an if node to sort out the ones containing wrong data. Two problems arise:

1. while switching items in the expression editor I get true and false values back from the expression but when I execute the node only false ones appear
2. I cannot create the return value of the expression with the right type. Neither does (!isNaN(date)) produce a boolean not does return false or return “false” produce a string - confusing

What is the error message (if any)?

Item 0 returns false

Item 1 returns true

Output is all false??

Please share your workflow

Share the output returned by the last node

Expected output would be 2 false and 23 true output items.

Information on your n8n setup

• n8n version: 1.110.1
• Database (default: SQLite): default cloud
• n8n EXECUTIONS_PROCESS setting (default: own, main): default for n8n cloud
• Running n8n via (Docker, npm, n8n cloud, desktop app): n8n cloud
• Operating system: mozilla on win

[jabbson]

Please see if this helps:

[Cenitor]

Well, thank you jabbson, that does work like a charm but why isn’t mine?

[jabbson]

I just looked at it and was like - nope, I am not digging into that, let me rewrite

[Cenitor]

I understand that but I would like to get an idea how the IIFE syntax resolves return values because I think that’s where the problem with my approach and I won’t be able to solve everything with one statement

[jabbson]

In case you need to do code, just do code - make it simple, readable and reusable:

[Cenitor]

Agreed, thanks !