How to iterate on an array and extract value in nifi?

hi @anony,
Is this the content of your FlowFile coming from the API as a response?
If yes, you could split your array into several FlowFiles and process them in whatever order you would like.

I assume that you do not need your square brackets and your double quotes for your processing so you could use a ReplaceText to remove all of them.

In your ReplaceText Processor, you need to define a java regex which will perform this remove of double quotes and square brackets.

If you do not succeed in writing that java regex, you can try a combination of 4 ReplaceText processors:
- the first one defined as Search Value = " and Replacement Value set to empty string. Make sure you use Replacement Strategy = Literal Replace.
- the second one defined as Search Value =   (empty space here) and Replacement Value set to empty string. Make sure you use Replacement Strategy = Literal Replace.
- the third one defined as Search Value = [ and Replacement Value set to empty string. Make sure you use Replacement Strategy = Literal Replace.

- the forth one defined as Search Value = ] and Replacement Value set to empty string. Make sure you use Replacement Strategy = Literal Replace.

Once you removed all those, proceed with using a SplitContent, defined as follows:
- Byte Sequence Format = Text

- Byte Sequence = ,

This will send forward in your stream a flowfile containing each value from your initial Array.
Basically you will have 12 flowfiles, each with one value from your initial array.

PS: as you did not provide any information regarding the scope of your iteration, I have somehow ignored it as I did not fully understand what you meant.