The Java TM Tutorial

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Trail: Writing Applets
Lesson: Taking Advantage of the Applet API

## Defining and Using Applet Parameters

> Parameters are to applets what command-line arguments are to applications. They allow the user to customize the applet's operation. By defining parameters, you can increase your applet's flexibility, making your applet work in multiple situations without recoding and recompiling it.

> The next few pages discuss parameters from the applet programmer's point of view. To learn about the user view of parameters, see Specifying Parameters.

### Deciding Which Parameters to Support

> When implementing parameters, you must answer four questions:
> - What should the applet let the user configure?
> - What should the parameters be named?
> - What kind of value should each parameter take?
> - What should the default value of each parameter be?

### Writing the Code to Support Parameters

> Applets get the user-defined values of parameters by calling the `Applet` `getParameter` method.

### Giving Information about Parameters

> By implementing the `getParameterInfo` method, applets provide information that browsers can use to help the user set parameter values.

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