Concatenate All Values Into Constant

*(Q) I have a string variable var1 that may contain entries x_1 to x_n
interspersed with missing values (n is unknown in advance). I would
like to create a new constant string variable newvar which is simply a
concatenation of all the non sysmissing values in var1.

*(A) By rlevesque@videotron.ca 2001/10/09.

DATA LIST LIST /var1(A8).
BEGIN DATA
.         
x1        
.         
.         
x2        
x3        
.         
x4        
.         
.         
END DATA.
LIST.

COMPUTE dummy=1.
SAVE OUTFILE='c:\\temp\\mydata.sav'.

SELECT IF LTRIM(RTRIM(var1))<>".".
COMPUTE idx=$CASENUM.
STRING newvar(A255).
DO IF idx=1.
COMPUTE newvar=var1.
ELSE.
COMPUTE newvar=CONCAT(RTRIM(LAG(newvar))," ",var1).
END IF.
EXECUTE.

COMPUTE dummy=1.
ADD FILES FILE=* /BY=dummy /LAST=last.
EXECUTE.
SELECT IF last=1.
SAVE OUTFILE='c:\\temp\\mystring.sav'.
GET FILE='c:\\temp\\mydata.sav'.
MATCH FILES FILE=* /TABLE='c:\\temp\\mystring.sav' /BY dummy.
* Clean up.
MATCH FILES FILE=* /DROP=dummy idx.
EXECUTE.