Unable to determine length of array in a Velocity User Macro ?

Question

This should be a really simple thing to do - determine the length of an array in Confluence/Velocity - but I'm struggling to figure it out!

I've tried 3 ways to find the length of an array (shown below) and the only way that works is via Method 3 (a horrible loop?)

N.B. the $list is a reference to (hopefully) the ListTool library, is it included in Confluence's version of Velocity? If not, how can I add it?

Can someone slap me upside the head and tell me what's wrong here?

Thanks

The Example Code

#set($keys = "AAA,BBB,CCC,DDD")

## Method 1
#set($arrayKeys = $keys.split(",")) 
#set( $countBySize = $arrayKeys.size() )

## Method 2
#set( $countbyList = $list.size($arrayKeys))

## Method 3
#set($countByKeys = 0) 
#foreach ($key in $arrayKeys) 
   #set($countByKeys = $countByKeys + 1) 
#end

The Results as Rendered

N.B. numKeys in the table should be countByKeys

Garry May · Answer

Hi Adriian, thanks for getting back to me.  The probably I have is a bit misleading in that I'm getting a comma separated string of keys from a User Macro parameter, i.e. a single string like "A,B,C" which is different to how you've initialised your array. I use the split function to return the array of keys....but the subsequent call to the size() function doesn't seem to be recognised when I evaluate it?  What am I missing?

The split function returns ($arrayKeys, as per the table of results)

"[Ljava.lang.string:@xxxxx" Is this an array reference or simple a long string?

Thanks

Adriian Semotiuk · Answer

Hello @Garry May , 
First of all Velocity Templates supports arrays as type of variable , so you can initialize array as this, so you would not be splitting string into array

#set($array = ["AAA","BBB","CCC","DDD"])

And since Velocity Template supports interaction with Collection API VTL Reference , we can use method size() on all Collection classes, so code like this should work

#set($array = ["AAA","BBB","CCC","DDD"])
Size of an array: $array.size()

Hope this will resolve your issue