Flash Player 5.
typeof(expression)
expression A string, movie clip, button, object, or function.
Operator; a unary operator placed before a single parameter. The typeof operator causes the Flash interpreter to evaluate expression; the result is a string specifying whether the expression is a string, movie clip, object, function, number, or Boolean value. The following table shows the results of the typeof operator on each type of expression:
| Parameter | Output |
| String | string |
| Movie clip | movieclip |
| Button | object |
| Text field | object |
| Number | number |
| Boolean | boolean |
| Object | object |
| Function | function |