Understanding the ActionScript Language > Using Flash MX ActionScript with older versions of Flash > Using Flash MX to create content for Flash Player 4 |  |

Using Flash MX to create content for Flash Player 4

To use Flash MX to create content for Flash Player 4, set the export version to Flash 4 when you publish your movie. Flash 4 ActionScript has only one basic primitive data type, which is used for both numeric and string manipulation. When you author a movie for Flash Player 4, you must use the deprecated string operators located in the Deprecated > Operators category in the Actions toolbox.

You can use the following Flash 5 and Flash MX features when you export to the Flash 4 SWF file format:

| The array and object access operator (`[]`)
| The dot operator (`.`)
| Logical operators, assignment operators, and pre-increment and post-increment/decrement operators
| The modulo operator (`%`), and all methods and properties of the Math object
| These operators and functions are not supported natively by Flash Player 4. Flash MX exports them as series approximations, which creates results that are less numerically accurate. In addition, because of the inclusion of series approximations in the SWF file, these functions take up more room in Flash 4 SWF files than they do in Flash 5 or later SWF files.
| The `for`, `while`, `do..while`, `break`, and `continue` actions
| The `print` and `printAsBitmap` actions
| The `switch` action

The following ActionScript features can't be used in movies exported to the Flash Player 4 file format:

Built-in objects (except Math) | `isFinite` | `localToGlobal` | `parseFloat` | `typeof`
Custom functions | `isNaN` | Local variables | `parseInt` | `unescape`
`delete` | `for..in` | Movie clip methods | `_quality` | XML elements
`escape` | `globalToLocal` | Multiple data types | `return` | `_xmouse`
`eval` with dot syntax—for example, `eval("_root.movieclip.variable")` | `hitTest` | `new` | `targetPath` | `_ymouse`