Conditional expresion in query

I have been reading about contidional expresions in a query and I have a
question about the following example included in the documentation:

SELECT a,
CASE WHEN a=1 THEN 'one'
WHEN a=2 THEN 'two'
ELSE 'other'
END
FROM test;

I would like to make a few changes but I need to give a name (an alias) to
the result of the CASE. Can an "AS" be added as shown below?

SELECT a, b,
CASE WHEN a=b THEN a
ELSE a || '-' || b
END AS ab
FROM test;

Respectfully,
Jorge Maldonado