Loops In Appian

Hello Today we will be having a look at Looping Functions Available in Appian WIth their Use cases.

• a!forEach
• apply
• all
• any
• filter
• merge
• none
• reduce
• reject

Let’s Start with All Time Famous

>>a!forEach

Here we are Trying to Find Multiples of 3
a!forEach(items: enumerate(10)+1,expression: fn!product(3,fv!item)),

• fv!item (Any Type): The current item
• fv!index (Integer): The current item’s index in the items array
• fv!identifer (Any Type Array): When items are a DataSubset with identifiers, the current item’s identifier, otherwise null
• fv!isFirst (Boolean): True for the first item in the items array, otherwise false
• fv!isLast (Boolean): True for the last item in the items array, otherwise false
• fv!itemCount (Integer): The total number of items (including nulls)

With Help of Apply we are aslo able to achive the same Output
apply(fn!product,{enumerate(17)+1},3)

>>apply

With Help of Apply we are aslo able to achive the same Output
apply(fn!product,{enumerate(17)+1},3)

When we Try to Compare both Blocks Of Code we can easily Reduce the blocks of Code by Using Appian Given Functions.

>> all

all( a!isNotNullOrEmpty, {1, 2, null, 3, null, 4} )

It will keep Dive and Check for All saving iteration time with an Overall One Result.

>> any()

It can be considered the Opposite of all Function

ex: any( a!isNullOrEmpty, {null, 1, 2, 3, 4, 5} ) It will check if any of the desired Function results exists.

>> filter()

filter( predicate, list, context )

ex : filter(a!isNotNullOrEmpty,{1, 2, null, 3, null, 4})

>> merge

It takes the Number of Lists and merges them into a single list.

Additional info We also have such function for strings named tostring() and for multiple we can make use of touniformstring()

>> none

Note: we have limitations with this function i.e we cannot use a!forEach() with none()

ex : none(a!isNullOrEmpty,{1, 2, null, 3, null, 4})

>> reduce

ex: reduce( fn!substitute, “abcdefg”, {“a”, “d”, “f”}, “#” )

>> reject

ex : reject( a!isNullOrEmpty, {1, 2, null, 3, null, 4} )

These are Looping Functions that Play a vital role in optimizing the code and making fewer iterations.

We Can Also Design Our Custom Loop Using a Process Model in Appian By Handling Counter Variables and Checking conditions using Gateways.

Have a best Day Guys.