Shuffling an array randomly

Question

I have an array of CDTs say questions with question structured as: 
 { 
 id: 1, 
 statement: "Text string of question", 
 options: {List of Options} 
 } 
 Like multiple values like the above. 
 
 I would like to shuffle this array of questions randomly so that every time I print this array the questions are in no particular order and are different from last time. Example if I pick the array first time it had an order: 
 1, 4, 2, 5, 3 
 But next time I pick same array it should be ordered randomly like: 
 3, 5, 1, 4, 2 
 Also is there any possible way to implement Rand() ordering in the query like we do in SQL?

Mike Schmitt · Accepted Answer

There are various ways to do this, but anything you do you'll have to build yourself. 
 A quick-and-dirty way I just thought of: 
 
 use a!forEach to loop over the CDT array and use updateDictionary() to add a new ad-hoc property to each one, i.e. "order", set to the value of a rand() call. This will give a random decimal between 0 and 1 to all items; they should almost always be unique as far as I know. 
 Sort the array based on the "order" decimal (use the "toDataSubseet" trick to sort an array of dictionary based on the value of a property).

Mike Schmitt · Answer

Something like that would need to be built into the a!queryEntity function or one of its components - you could always file a feature request ticket with Appian Support, however I wouldn't expect it to be prioritized anytime soon without a strong use case on your end. 
 Out of boredom I went ahead and implemented a standalone function where you input the desired number of items and it returns a randomized list of integer indices 1...N, where we're guaranteed to have no duplicates or missing numbers. This integer array could then be used to index into any particular array in a randomized manner. 
 a!localVariables(
 
 local!targetSize: 25,
 
 local!dict: a!forEach(
 enumerate(local!targetSize),
 
 a!map(
 integer: fv!index,
 sort: rand()
 )
 ),
 
 local!sorted: todatasubset(
 local!dict,
 a!pagingInfo(
 startIndex: 1, batchSize: -1,
 sort: a!sortInfo(field: "sort", ascending: true())
 )
 ),
 
 local!sorted.data.integer
)

Shuffling an array randomly

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