Boolean()

Flash Player 5; behavior changed in Flash Player 7.

Boolean(expression)

expression An expression to convert to a Boolean value.

A Boolean value or the value expression, as described below.

Function; converts the parameter expression to a Boolean value and returns a value as follows:

If expression is a Boolean value, the return value is expression.

If expression is a number, the return value is true if the number is not zero, otherwise the return value is false.

If expression is a string, the return value is as follows:

In files published for Flash Player 6 or earlier, the string is first converted to a number; the value is true if the number is nonzero, false otherwise.
In files published for Flash Player 7 or later, the result is true if the string has a length greater than zero; the value is false for an empty string.

If expression is undefined, the return value is false.

If expression is a movie clip or an object, the return value is true.