Java Reference
In-Depth Information
One approach to reading keyboard input is to read an entire line of input into a
variable of type
String
—for example, with the method
nextLine
of the
Scanner
class—and then to use the
StringTokenizer
class to decompose the string in the vari-
able into words.
The class
StringTokenizer
is in the standard Java package (library)
java.util
. To
tell Java where to find the class
StringTokenizer
, any class or program that uses the
class
StringTokenizer
must contain the following (or something similar) at the start
of the file:
import
java.util.StringTokenizer;
import
Perhaps the most common use of the
StringTokenizer
class is to decompose a
line of input. However, the
StringTokenizer
class can be used to decompose any
string. The following example illustrates a typical way that the class
StringTokenizer
is used:
StringTokenizer wordFactory =
new
StringTokenizer("A single word can be critical.");
while
(wordFactory.hasMoreTokens())
{
System.out.println(wordFactory.nextToken());
}
This will produce the following output:
A
single
word
can
be
critical.
The constructor invocation
new
StringTokenizer("A single word can be critical.")
produces a new object of the class
StringTokenizer
. The assignment statement
StringTokenizer wordFactory =
new
StringTokenizer("A single word can be critical.");
gives this
StringTokenizer
object the name
wordFactory
. You may use any string in
place of
"A single word can be critical."
and any variable name in place of
word-
Factory
. The
StringTokenizer
object created in this way can be used to produce the
individual words in the string used as the argument to the
StringTokenizer
construc-
tor. These individual words are called
tokens
.
tokens