· Mar 10, 2020

Reducing the end variable in a FOR loop once executed

Dear All,

I'm looping through a list with characters (Parenthesis, square brackets etc) and I wish to remove these from the list.

The for loop and IF logic are effectively removing these items from a list.

However the variable I use for the maximum number of loops carries on beyond the number of items of the list after removal.

In the output value for these I get the integer of the for loop instead of a  null for the empty list fields.

I can see in the documentation that the end variable is not editable once the loop is started.

I looked at quitting out of the loop if the list value returned is null, but this isn't working either.

Any ideas please.



Discussion (12)4
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Excerpt of Code as Promised:

set list = "ABC~DEF~GHI~JKL~MNO~[~PQR~]"

set SegmentList = $LISTFROMSTRING(list,"~")
Set SegmentCount = $LISTLENGTH(SegmentList)
FOR i = 1:1:SegmentCount{
IF ($LISTGET(SegmentList,i,i)= "[") {
set $LIST(SegmentList,i,i)=""
set OptionalSegment = "Y" 
ELSEIF ($LISTGET(SegmentList,i,i)= "]") {
set $LIST(SegmentList,i,i)=""
ELSEIF ($LISTGET(SegmentList,i,i)= "") {
Write !, "Current Segment: "_$LISTGET(SegmentList,i,i)
Set SegmentFields = $LISTFROMSTRING(object.SegmentSubStructure,"~")
Set SegFieldCount = $LISTLENGTH(SegmentFields)
Hi Stuart

And using CONTINUE command ?

set list = "ABC~DEF~GHI~JKL~MNO~[~PQR~]"
set SegmentList = $LISTFROMSTRING(list,"~")
set SegmentCount = $LISTLENGTH(SegmentList)
set OptionalSegment="N"
FOR = 1:1:SegmentCount{
  if $LISTGET(SegmentList,i)= "[" set OptionalSegment = "Y" continue
  if $LISTGET(SegmentList,i)= "]" set OptionaSegment="N" continue
  write !, "Current Segment: "_$LISTGET(SegmentList,i)," ",OptionalSegment
  ;set SegmentFields = $LISTFROMSTRING(object.SegmentSubStructure,"~")
  ;set SegFieldCount = $LISTLENGTH(SegmentFields)

Hi Stuart,

As others have said, it's best practice to build a new variable, rather than amending what you have (there's some fancy name for the rule, I think, or maybe just "functional programming").

Looking at the string, I assume it is HealthShare HL7 message format, so the contents are pretty limited. In which case maybe a shortcut could be used:

s out=$Replace($Replace(list,"~]",""),"~[","")

Here's another alternative:

w $ZSTRIP($ZSTRIP(list,"*","[]"),"=>P")

I admit it could go horribly wrong with multiple nesting (I don't remember all the possible formats), so needs some testing. 

Hope you're keeping well,