Assignment to local variables in Expression rule

Question

Hi, 
 I'm trying to save an array value to a local variable, it looks like getting saved, but when I check for the length of the local variable, I'm getting as 0. Where as when I save the same array during declaration of the local variable, I'm getting the length as expected. 
 What I'm missing here ? what is the proper way of saving into local variables after declaring them. I've tried using a!save() but no luck.. :( 
 Below are the snaps for your reference. 
 Assigning array after initialization

Assigning array during initialization 
 
 TIA :)

Mike Schmitt · Accepted Answer

There are mainly only 2 places where you can "assign a value" to a local variable: 
 1) at declaration 
 2) as the result of a user interaction in an interface component 
 Seeing as this is an expression rule, and therefore #2 is irrelevant, you will need to assign the value at declaration (#1). 
 This is the most important concept here : There is no such thing , in Appian's expression language, as "define a blank local variable then in a later line of code give it a new value". If you know its initial value, then you will assign it at creation time.

Mike Schmitt · Answer

Vasudeva said: the value would come after initialization as a result of some equation 
 You would declare its value after any other calculations (usually declared as their own local variables) on which it depends.

Mathieu Drouin · Answer

The local variables section pretty much covers it. 
 docs.appian.com/.../Local_Variables.html

Mathieu Drouin · Answer

I think maybe having that variable being the key in the dictionary might be doing weird things. 
 Try this: 
 a!localVariables(
 local!parts: {
 a!map(
 partName: "part1",
 quantity: 1,
 unitCost: 1
 ),
 a!map(
 partName: "part2",
 quantity: 1,
 unitCost: 1
 )

 },
 {
 parts: local!parts,
 length: length(local!parts)
 }
)

Assignment to local variables in Expression rule

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