davido answered this excellently, so I'd like to whine about a pet peeve: using a quoted string as the first arg to split. I would write that as split(/foo/,split(/w00tx0r/,"bla foo w00tx0r moo"));.

Using "foo" instead of foo seems to create the false impression that split will work with either a regular expression or an exact string. Then you see things like split ".", which should really be split /\./.

Split only takes a regex (with the confusing exception of " "), so show it that way.