I have installed ruby with "ruby181-11.exe" on Windows XP and wanted to try
some code samples from the Ruby Programmers Guide, but without success. If I
run following code, I don't get any output on console:

------------------------------------
      a = [ 1, 'cat', 3.14 ]   # array with three elements
      # access the first element
      a[0]  ? 1
      # set the third element
      a[2] = nil
      # dump out the array
      a  ? [1, "cat", nil]
------------------------------------

Just the command "puts a" works.
Any idea?