How to create a variable indexed with the row number?

[Shradha1]

I have a dataset with one variable that is student roll number. All the observations are distinct and there are no duplicates. Now I want to create another variable indexed with the row number. Like if I have 15 rows with 15 different roll numbers. Then my new variable should take value c_1 against row 1, c_2 against row 2...and so on till c_15 against row 15. How do I acheive this? Thank you!

[PaigeMiller · Accepted solution]

data want;
    set have;
    newvariable=cats('c_',_n_);
run;

... if I am understanding you properly

If I may be so bold as to point out a disadvantage of doing things this way ... NEWVARIABLE doesn't sort properly, if you sort NEWVARIABLE it will come out as

c_1

c_10

c_11

c_12

c_13

c_14

c_15

c_2

and so on

Why don't you just make newvariable numeric and assign it integers 1 through 15?

[ballardw]

Or control the values a bit better:

data want;
    set have;
    newvariable=cats('c_',put(_n_, z2.));
run;

Assuming you know there are fewer than 100 records.

This gives you C_01, C_02, ... C_15.

Which will sort properly and, IMHO, looks a bit nicer.