Um, no it doesn't. It works as expected, even the loop shows that.
String a = "some phrase";
String b = a.split(" ");
for (String s : b)
System.out.println("String part: " + s);
System.out.println("Position 0: " + b);
System.out.println("Position 1: " + b);
String part: some
String part: phrase
Position 0: some
Position 1: phrase
BTW, if you are returning results of b as:
That indicates your string is not separated by a space, rather its separated by a linefeed.