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;I am calling f() in the same line as a loop parsing the variable string.
;What I want is for f() to change the value of string (by using byref parameters) before the loop starts working.
;i.e. the loop should display letters, because that is the value set in f(), instead of numbers, which is the value set before the parsing loop
;---------------------------------------------------------------------
;In this example, the parsing loop receives the initial value of string as set in the line before the parsing loop:
string = 1.3.5.7 ;7 characters
Loop, Parse, string, % f(string)
   MsgBox, % A_LoopField
;---------------------------------------------------------------------
;HOWEVER, as long as string contains a value of length at least 8 before the line containing the parsing loop, it seems to work
string = 1.3.5.78 ;8 characters
Loop, Parse, string, % f(string)
   MsgBox, % A_LoopField

;---------------------------------------------------------------------
;here's the function
f(ByRef var)
{
   var := "a.b.c.d.e"
   Return "."
}

#NoEnv
;I am calling f() in the same line as a loop parsing the variable string.
;What I want is for f() to change the value of string (by using byref parameters) before the loop starts working.
;i.e. the loop should display letters, because that is the value set in f(), instead of numbers, which is the value set before the parsing loop
;---------------------------------------------------------------------
;In this example, the parsing loop receives the initial value of string as set in the line before the parsing loop:
string = 1.3.5.7 ;7 characters

;---------------------------------------------------------------------
;HOWEVER, as long as string contains a value of length at least 8 before the line containing the parsing loop, it seems to work
;~ string = 1.3.5.78 ;8 characters


msgbox before Loop %string%
Loop, Parse, string, % f(string)
{
   if A_Index = 1
      msgbox in loop %string%
   MsgBox, % A_LoopField
}

;---------------------------------------------------------------------
;here's the function
f(ByRef var)
{
   msgbox before change %var%
   var := "a.b.c.d.e"
   msgbox after change %var%
   Return "."
}

VarSetCapacity(string, 256)

VarSetCapacity( data, 1250, 0 )
data := "1.2.3.4"
Loop, Parse, data, ., % g( data )
   data .= "," A_LoopField
msgbox % data

g( byref var ) {
StringReplace, var, var, ., .., a
Return ""
}

VarSetCapacity(ErrorLevel, 256) ; Does not affect the result.
ErrorLevel = 1.3.5.7
Loop, Parse, ErrorLevel, % f1(ErrorLevel)
    MsgBox % A_LoopField ; Shows 1, 3, 5, 7
MsgBox % ErrorLevel ; Shows a.b.c.d.e
f1(ByRef var) {
    var := "a.b.c.d.e"
    return "."
}

VarSetCapacity(var, 256) ; Use dynamic memory.
MsgBox 0,
; &var is stored at this point:
, %var%
; Freeing var invalidates the previous arg. There is also a possibility that
; 'junk' will receive the block of memory which previously belonged to var:
, % VarSetCapacity(junk`, 256 + VarSetCapacity(var`, 0)`, 1) * 0