D-E > eval |
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eval
Availability
Flash Player 5 or later for full functionality. You can use the eval
function when exporting to Flash Player 4, but you must use slash notation, and can only access variables, not properties or objects.
Usage
eval(
expression
);
Parameters
expression
A string containing the name of a variable, property, object, or movie clip to retrieve.
Returns
Nothing.
Description
Function; accesses variables, properties, objects, or movie clips by name. If the expression
is a variable or a property, the value of the variable or property is returned. If the expression
is an object or movie clip, a reference to the object or movie clip is returned. If the element named in the expression
cannot be found, undefined
is returned.
In Flash 4, the eval
function was used to simulate arrays; in Flash 5, it is recommended that you use the Array object to simulate arrays.
You can also use the eval
function to dynamically set and retrieve the value of a variable or instance name. However, you can also do this with the array access operator ([]
).
Note: The ActionScript eval
action is not the same as the JavaScript eval
function, and cannot be used to evaluate statements.
Example
The following example uses the eval
function to determine the value of the expression
"piece
" + x
. Because the result is a variable name, piece3
, the eval
function returns the value of the variable and assigns it to y
:
piece3 = "dangerous"; x = 3; y = eval("piece" + x); trace(y); // Output: dangerous
See also
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