Why the Set node returns a length of an array instead of the array itself?

[honzapav]

Hello friends!
I have this code in an expression in the Set node.

{{
$node["Item Lists"].json["pledge"]["isRecurrent"] === 'false'
? $json["fields"]["Seznamy kontaktů"].push('recx2v1IUczJc7Fsv') 
: $json["fields"]["Seznamy kontaktů"].push('recdzgujTppgs1vrE')
}}

The Set node returns a length of the array instead of the array itself. Also, the number is increasing when interacting with the workflow. The original array has two items, I am adding a third one – the length is 88 and increasing.

Can you please suggest how to resolve this?
Thank you.
H.

[jan]

Has actually nothing to do with how n8n works, but rather how JavaScript works and what push returns (which is the new length of the array it pushed to):

Here an example:

Here are the docs of push:

Array.prototype.push() - JavaScript | MDN

[honzapav]

Hi @jan – I was so sure this method returns the array, so I even did not check the docs. This is stupid, sorry and thanks!

[jan]

Ah and regarding the second part. How to do it. Normally you could do something like this:

[...$json["fields"]["Seznamy kontaktů"], 'recx2v1IUczJc7Fsv']

but honestly do not know right now why it does not work in n8n.

In this case probably best to use a Code-Node.