Loop Until does not stop when the condition is met

[Anonymous]

I have a Loop Until action in my flow that reads each element of a JSON array, and builds a new JSON object out of it. The loop is supposed to run until the value of the VersionLabel element is 1.0. The problem is, the loop isn't exiting once the value is reached. I've tested it multiple times, using no quotes around the 1.0, using single and double-quotes, but no luck. The loop tries to go onto the next element of the JSON array, and then errors out, because there are no more elements (the element with a VersionLabel value of 1.0 is always the last element in the array). Any idea what's going on?

I couldn't get the tooltip to appear in my screenshot, but the expression in the left side of the loop condition is...

body('Parse_JSON')?['d']?['results'][variables('intCounter')]['VersionLabel']

The counter variable is incremented at the end of each loop, so when it gets high enough to reach the last element of the array, that expression should return 1.0, and the loop should immediately exit when the condition is evaluated, right?

[RezaDorrani · Accepted solution]

Hi @Anonymous 

condition use edit in advanced mode and try this

or(equals(body('Parse_JSON')?['d']?['results']?[variables('intCounter')]?['VersionLabel'],'1.0'),equals(body('Parse_JSON')?['d']?['results']?[variables('intCounter')],null)

checking to see both if next value exists or if version is 1.0

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[Anonymous]

Thank you, @RezaDorrani! That check for a null element was the trick. A couple questions, though, so I'm sure I understand how this is working...

When the loop exits, it exits before processing the information in that final element (when VersionLabel = "1.0"). How could I modify the condition so that the exits after processing the final element? I tried removing the first portion, and leaving the check for a null element, but that resulted in the same error as before. The workaround I've used is to separately process the final element by directly referencing it using the value of the intCounter variable. It works, but it seems like there's a better way to do it.

My second question is why did this solution work? Without the check for the null element, the condition fails. When checking for a null element, but without the value check, the condition fails. Why are both conditions needed for this to succeed?

Thanks again!