Possible Duplicate:
What is the * operator doing to this string in Ruby
Probably there is answer for that elsewhere, but I just don't know how to find it...
If I am right, the * means multiple parameters if used in function definition:
def hero(name, *super_powers)
But what does * do in the code like this:
Hash[*[[:first_name, 'Shane'], [:last_name, 'Harvie']].flatten] # => {:first_name=>"Shane", :last_name=>"Harvie"}
Variable Length Argument List, Asterisk Operator
The last parameter of a method may be preceded by an asterisk(*), which is sometimes called the 'splat' operator. This indicates that more parameters may be passed to the function. Those parameters are collected up and an array is created.
The asterisk operator may also precede an Array argument in a method call. In this case the Array will be expanded and the values passed in as if they were separated by commas.
来源：https://stackoverflow.com/questions/4170037/what-does-the-star-mean-in-ruby