SAS Component Language Dictionary |
Reports the length of an SCL list
-
n
-
contains either the length of an SCL list
or status information:
>0 |
the length of a non-empty list |
0 |
the list is empty |
-1 |
the list identifier is invalid. |
Type:
Numeric
-
list-id
-
is the identifier of the list whose length
is being queried, or any other number.
Type: Numeric or List
The length of a list is the number of items in the list,
excluding the contents of sublists. Because LISTLEN returns -1 if list-id is an invalid list identifier, you can use LISTLEN
to determine whether a list exists. For example:
listid=getniteml(envlist('G'),'MYLIST');
invalid=(listlen(listid)=-1);
if invalid then
do;
put 'MYLIST in the global environment has been deleted.';
stop;
end;
Create the empty list LISTA, and then insert LISTA into
a copy of itself, LISTB. The lengths of the two lists are then computed and
are stored in the variables LEN_A and LEN_B.
lista=makelist();
listb=copylist(lista);
listb=insertl(listb,lista);
len_a=listlen(lista);
len_b=listlen(listb);
_msg_='The length of LISTA is '||len_a||' and '||
'the length of LISTB is '||len_b;
This example shows that the length of LISTA is 0, whereas
the length of LISTB is
1.
MAKELIST
MAKENLIST
Copyright © 2011 by SAS Institute Inc., Cary, NC, USA. All rights reserved.