How to calculate many sums in a single foreach relating the same data?

Why not just have the forEach loop construct a dictionary?  You can at least condense it down to only a single a!forEach loop over ri!data, though I don't immediately think of any way to do all the sum() operations in the same spot (but they're simpler at least)

i.e.

local!dictionary: a!forEach(
  items: ri!data,
  expression: {
    partA: if(fv!item.weight > 0, 1, 0),
    partB: if(fv!item.weight > fv!item.weight2, 1, 0),
    weight1: fv!item.weight,
    weight2: fv!item.weight2
  }
),

local!sumA: sum(local!dictionary.partA),
local!sumB: sum(local!dictionary.partB),
local!sumC: sum(local!dictionary.weight1),

...

I agree with Mike . even i don't think of other option . This would have been easier and can be done in single For each in Java Programming. 

There is an option using reduce() which allows you to pass data from one iteration to the next. I used it to implement a block based checksum algorithm for IBAN validation. But in this case I would prefer this simple one.

Thank you Mike, sugasanr.
It's great ! I did not know we could do that with a dictionnary.

Thanks Stefan, I keep this function on hand :-)

Hi Stefan, 

do you still have the code for checksum algorithm for IBAN Validation in Appian?

You would be of great help to me.

Thanks!

Sure. Please connect me here in Appian community and let's have a direct chat.

Hi Stefan, me too I need this solution for a IBAN validation!!!... Thanks

The implemented algorithm is

https://en.wikipedia.org/wiki/International_Bank_Account_Number#Modulo_operation_on_IBAN

The trick here is, to use the initial parameter of the reduce function like a shared memory dictionary which is modified on each iteration.

Have fun :-)

IsIbanValidHelper: dict(any)
if(
  isnull(ri!dict.bban),
  ri!dict,
  a!localVariables(
    local!checksum: mod(tostring(ri!dict.checksum) & left(ri!dict.bban, ri!dict.num), 97),
    local!bban: right(ri!dict.bban, len(ri!dict.bban) - tointeger(ri!dict.num)),
    {
      checksum: local!checksum,
      num:7,
      bban: local!bban
    }
  )
)

IsIbanValid: iban(text)
a!localVariables(
  local!iban: upper(stripwith(ri!iban, " ")),
  local!checksum: left(local!iban, 4),
  local!ban: right(local!iban, len(local!iban) - 4),
  local!bban: local!ban & local!checksum,
  local!replaceChars: {touniformstring(enumerate(10)), "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"},
  local!replaceNums: {enumerate(10), enumerate(26)+10},
  local!newbban: joinarray(
    a!forEach(
      items: enumerate(len(local!bban)),
      expression: displayvalue(
        local!bban[fv!index],
        local!replaceChars,
        local!replaceNums,
        ""
      )
    )
  ),
  local!result: reduce(
    rule!IsIbanValidHelper(
      dict:_,
      dummy:_
    ),
    {
      checksum: 0,
      num: 9,
      bban: local!newbban
    },
    enumerate(ceiling(len(local!newbban) / 7))
  ),
  tointeger(local!result.checksum) = 1
)

Thank you Stefan Helzle, this will help me a lot!!!!