Pointer on repeated measurements

[NewUsrStat]

suppose to have the following:

Value
1
1
1
2
2
2

How can I say/indicate: the last 1 before 2 and the first 2 after the last 1? Thank you in advance

[PaigeMiller · Accepted solution]

You can use FIRST. to find the first value in a group and LAST. to find the last value in a group. Example:

data want;
    set have;
    by value;
    if last.value then do; ...; end;
    if first.value then do; ...; end;
run;