MACROMEDIA FLEX-FLEX ACTIONSCRIPT LANGUAGE Reference page 129

Boolean()
Availability
Flash Player 5; behavior changed in Flash Player 7.
Usage
Boolean(expression) : Boolean
Parameters
An expression to convert to a Boolean value.
expression
Returns
A Boolean value.
Description
Function; converts the parameter
in the following list:
•
If
expression
•
If
expression
return value is
If is a string, the result is
expression
for an empty string.
false
•
If
expression
•
If
expression
Note: Unlike the Boolean class constructor, the Boolean() function does not use the keyword new.
Moreover, the Boolean class constructor initializes a Boolean object to false if no parameter is
specified, while the Boolean() function returns undefined if no parameter is specified.
Example
In the following example, expressions are converted from numeric to Boolean values:
trace(Boolean(-1)); // output: true
trace(Boolean(0)); // output: false
trace(Boolean(1)); // output: true
trace(Boolean(true)); // output: true
trace(Boolean(false)); // output: false
trace(Boolean("true")); // output: true
trace(Boolean("false")); // output: true
trace(Boolean("Craiggers")); // output: true
trace(Boolean("")); // output: false
This example shows a significant difference between use of the
Boolean class. The
Boolean object. Boolean values are compared by value, and Boolean objects are compared by
reference.
ActionScript Core Language Elements
expression
is a Boolean value, the return value is
is a number, the return value is
.
false
true
is or (not a number), the return value is
undefined NaN
is a movie clip or an object, the return value is
function creates a Boolean value, and the Boolean class creates a
Boolean()
to a Boolean value and returns a value as described
expression
if the number is not zero; otherwise the
true
if the string has a length greater than zero; the value is
true
Boolean()
CHAPTER 5
.
.
false
.
function and the
Boolean() 129