[Chapter 2] 2.4 StringTokenizer

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| Chapter 2 Strings and Related Classes |

## 2.4 StringTokenizer

The `java.util.StringTokenizer` class provides support for parsing a string into a sequence of words, or tokens, that are separated by some set of delimiter characters. Here is an example of how to use the `StringTokenizer` class:

    StringTokenizer s = new StringTokenizer("This is it");
    while (s.hasMoreTokens())
        System.out.println(s.nextToken());

This example begins by creating a `StringTokenizer` object to pick tokens out of the specified string. The example uses a `StringTokenizer` constructor that does not specify what delimiters to use, so the new `StringTokenizer` object uses the default delimiters: space, tab (`'\t'`), carriage return (`'\r'`), and newline (`'\n'`).

The `while` loop does the actual work of getting the tokens from the `StringTokenizer` object. The `hasMoreTokens()` method returns `true` while there are still more tokens to be fetched from the `StringTokenizer` object, while `nextToken()` returns the next token. Here is the output from the example:

    This
    is
    it

You can also use a `StringTokenizer` to extract tokens from a string that uses delimiters other than whitespace. For example, suppose that you need to extract tokens that are separated by commas, such as from a string that looks like this:

    abc,def,123,789

In this case, you use a `StringTokenizer` constructor that takes a parameter that specifies the characters to be treated as delimiters. For example:

    StringTokenizer s = new StringTokenizer(commaString, ",");

The second argument to this constructor specifies the delimiter characters, so in this case, the only delimiter character is the comma character.

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