gistfile1.rb

def p(a)
  print a
  print "\n"
end

def a(ab, *test)
  p test.inspect
end

a(1,:ss => "123", :ab => 123)
a(2,1)
a(3)
a(4,nil)

b = *[]
p b.inspect

b = *nil
p b.inspect

b = *{}
p b.inspect

b = *{:a=>123,:b=>321,:c=>nil}
p b.inspect

b = *[1,2,3]
p b.inspect

b=*""
p b.inspect

b=*1
p b.inspect

output from ruby 1.8

[{:ss=>"123", :ab=>123}]
[1]
[]
[nil]
nil
nil
nil
[[:b, 321], [:c, nil], [:a, 123]]
[1, 2, 3]
nil
1

from jruby 1.6.5 (ruby 1.8.7)

[{:ss=>"123", :ab=>123}]
[1]
[]
[nil]
nil
nil
nil
[[:a, 123], [:b, 321], [:c, nil]]
[1, 2, 3]
nil
1