Chapter 4. How It Works
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## Chapter 4. How It Works

Everything you do with `JSAP` leads to the same goal: a `JSAPResult` object that contains objects created from the parsed command line. Getting to this point requires the following steps:

## Creating a JSAP to do the parsing.

This is generally accomplished through `JSAP`'s no-argument constructor. Depending upon the complexity of your program, however, you may want to instantiate a custom `JSAP` subclass that also takes care of steps 2 and 3 (described below) during the construction process. This approach results in a much "cleaner" main class. Another helpful class is `SimpleJSAP`, which provides on-the-fly declaration of program name, description, and parameters.

### Tip

If you have a complicated command line configuration, create your own subclass of `JSAP` and override its constructor so it can initialize itself. This keeps your main class uncluttered.

As of version 2.0, there is an experimental mechanism to load a fully configured JSAP from a simple XML file. See this section for details.

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