Console Input and Output - Absolute Java - page 87

Other Input Delimiters
When using the Scanner class for keyboard input, you can change the delimiters that
separate keyboard input to almost any combination of characters, but the details are a bit
involved. In this topic, we will describe only one simple kind of delimiter change. We will
tell you how to change the delimiters from whitespace to one specific delimiter string.
For example, suppose you create a Scanner object as follows:

Scanner keyboard2 = new Scanner(System.in);
You can change the delimiter for the object keyboard2 to "##" as follows:

keyboard2.useDelimiter("##");
After this invocation of the useDelimiter method, "##" will be the only input
delimiter for the input object keyboard2 . Note that whitespace will no longer be a
delimiter for keyboard input done with keyboard2 . For example, suppose the user
enters the following keyboard input:

one two##three##
The following code would read the two strings "one two" and "three" and make
them the values of the variables word1 and word2 :

String word1, word2;
word1 = keyboard2.next();
word2 = keyboard2.next();
This is illustrated in Display 2.10. Note that you can have two different objects of the
class Scanner with different delimiters in the same program.
Note that no whitespace characters, not even line breaks, serve as an input delimiter
for keyboard2 once this change is made to keyboard2 .

Self-Test Exercises

16. Suppose your code creates an object of the class Scanner named keyboard (as
described in this chapter). Write code to change the delimiter for keyboard to
a comma followed by a blank.

17. Continue with the object keyboard from Self-Test Exercise 16. Consider the

following input:

one,two three, four, five
What values will the following code assign to the variables word1 and word2 ?

String word1 = keyboard.next();
String word2 = keyboard.next();