Can you spot why the following program:

public class Split {
public static void main(String[] argv) {
String STRING = "foo  bar";
String[] s = STRING.split(" ");
for (int i = 0; i < s.length; i++) {
System.out.println(i + " '" + s[i] + "'");


0 'foo'
1 ''
2 'bar'

The reason is that split() works a little differently from StringTokenizer: 
it accepts a regular expression as a separator.  In the code above, I
define this regular expression as " " (one space character) but the input string
contains two of them.  Therefore, we can solve this problem by using the "
+" as a regular expression ("at least one space character").

Still, the fact that split() can return empty strings is deceiving,
especially if you are converting your code from StringTokenizer.

are a couple of good things about this behavior, though:

  • You can reconstitute
    the original string if you need to.
  • It makes it easier to parse strings with records that can
    be empty, such as lines from a log file.

Can you think of any other use?