Question

How can I add a prefix to all array elements except the first and last ones?

Is there a one line solution to that? Or a ‘nicer’ solution than mine?

result = ["svn up", "20111128025010", "20111128025022", "pass"]
for i in 1..result.length-2
  result[i]=" - "+result[i]
end

Answer 1

You could do it like this:

result[1 ... -1].each { |s| s[0, 0] = ' - ' }

Note that there are three dots, not two. This works because s[0,0] modifies s in-place. If you’re using 1.9.3+, you could also (and probably should) use prepend:

result[1 ... -1].each { |s| s.prepend(' - ') }

And, as the Tin Man notes in the comments, you could also use the double-dot range operator which is more common:

result[1 .. -2].each { |s| s[0, 0] = ' - ' }
result[1 .. -2].each { |s| s.prepend(' - ') }

Which range operator you use is a matter of preference.