Function with multiple parameters

Getting Started
1

Very very basic question: is it possible to pass multiple parameters to a function and have it return multiple results somehow?
In case, how should the syntax (both for the passing call and for the returned results) be?
Thank you

2

Passing multiple parameters is simple:

Function MyFunction (x As Integer, y As Text, z As Text) As Something

for example. You can also do something like this:

Function MyFunction (x As Integer, ParamArray someText() As Text) As Something

You can call this as x = MyFunction( 3, "A", "B", "C", "D" ) and those text values will populate the someText() array.

As for passing back multiple values, there are a few options. First, you can include ByRef parameters in the call that the method will populate, something like this:

Sub MyMethod (x As Integer, y As Text, ByRef return1 As Integer, ByRef return2 As Text )
  return1 = x
  return2 = y
End Sub

//
// Call this like:
//
dim x as integer
dim y as text
MyMethod 5, "hi", x, y

//
// x and y will now be populated
//

Or you can use a function that returns an array, Dictionary, or instance of a class you define that has properties for the various values.

4

for multiple return values, you can use the tuple class

[code]Class Tuple
Methods
Sub Constructor(items() as Variant)
for each item as Variant in items
self.Elements.Append item
next
End Sub

Function Operator_Compare(t as Tuple) As Integer
if t is nil then
return 1
else
if self.Count > t.Count then
return 1
elseIf self.Count < t.Count then
return -1
else
dim cmp as Integer = 0
for i as Integer = 0 to UBound(self.Elements)
if self.Elements(i) > t.Elements(i) then
cmp = 1
exit
elseIf self.Elements(i) < t.Elements(i) then
cmp = -1
exit
else
//continue
end if
next
return cmp
end if
end if
End Function

Sub Operator_Convert(p as Pair)
dim items() as Variant
if p <> nil then
do
items.Append p.Left
if p.Right isA Pair then
p = p.Right
else
items.Append p.Right
exit
end if
loop
end if
self.Constructor(items)
End Sub

Function Operator_Subscript(offset as Integer) As Variant
return self.Elements(offset)
End Function

Properties

Count As Integer

Get
return 1 + UBound(self.Elements)
End Get
Set

End Set

Private Elements() As Variant

Read Me
Tuple is an extension of the Pair class that holds more than two objects. A Tuple is not the same as a list object; it is intended to
represent a group of objects as a single entity.
You can use Pair syntax to create a Tuple.
dim t as Tuple = 1 : 2 : 3
It supports subscript access to its elements:
print t(1)
Tuple indices start at 0.

End Class[/code]

5

retrieved it : this tuple class came from here :
https://github.com/rustymyers/scripts/blob/master/Xojo/PrefTest/macoslib/Tuple.xojo_code

1 Like
6

Thank you everybody for your excellent suggestions