FLASH® LITE™ 2.x - Adobe Help and Support

Type checking on dynamic classes is less strict than type checking on nondynamic classes,
because members accessed inside the class definition and on class instances are not compared
with those defined in the class scope. Class member functions, however, can still be type
checked for return type and parameter types. This behavior is especially useful when you work
with MovieClip objects, because there are many different ways of adding properties and
objects to a movie clip dynamically, such as MovieClip.createEmptyMovieClip() and
MovieClip.createTextField().
Subclasses of dynamic classes are also dynamic.
Example
In the following example, class Person2 has not yet been marked as dynamic, so calling an
undeclared function on it generates an error at compile time:
class Person2 {
var name:String;
var age:Number;
function Person2(param_name:String, param_age:Number) {
trace ("anything");
this.name = param_name;
this.age = param_age;
}
}
In a FLA or AS file that's in the same directory, add the following ActionScript to Frame 1 on
the Timeline:
// Before dynamic is added
var craig:Person2 = new Person2("Craiggers", 32);
for (i in craig) {
trace("craig." + i + " = " + craig[i]);
}
/* output:
craig.age = 32
craig.name = Craiggers */
If you add an undeclared function, dance , an error is generated, as shown in the following
example:
trace("");
craig.dance = true;
for (i in craig) {
trace("craig." + i + " = " + craig[i]);
}
/* output: **Error** Scene=Scene 1, layer=Layer 1, frame=1:Line 14: There is
no property with the name 'dance'. craig.dance = true; Total ActionScript
Errors: 1 Reported Errors: 1 */
Add the dynamic keyword to the Person2 class, so that the first line appears as follows:
dynamic class Person2 {
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