MACROMEDIA FLASH 8-LEARNING ACTIONSCRIPT 2.0 IN FLASH, Руководство пользователя

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About functions and methods 211
About function literals
A function literal is an unnamed function that you declare in an expression instead of in a
statement. Function literals are useful when you need to use a function temporarily or to use a
function in your code where you might use an expression instead. The syntax for a function
literal is:
function (param1, param2, etc ) {
// statements
};
For example, the following code uses a function literal as an expression:
var yourName:String = "Ester";
setInterval(function() {trace(yourName);}, 200);
You can store a function literal in a variable to access it later in your code. To do so, you use an
anonymous function . For more information, see “Writing anonymous and callback functions”
on page 208 .
About constructor functions
The constructor of a class is a special function that is called automatically when you create an
instance of a class by using the
new
keyword (such as,
var my_xml:XML = new XML();
). The
constructor function has the same name as the class that contains it. For example, a custom
Person class that you create would contain the following constructor function:
public function Person(speed:Number) {
Person.nu+;
this._speed = speed;
}
Then you could create a new instance by using:
var myPerson:Person = new Person();
A class can contain only one constructor function; overloaded constructor functions are not
allowed in ActionScript 2.0. Also, a constructor function cannot have a return type. For more
information on writing constructor functions in class files,
“Writing the constructor function”
on page 268 .
NO
T
E
When you redefine a function literal, the new function definition replaces the old
definition.
NOT
E
If you do not explicitly declare a constructor function in your class file—that is, if you don’t
create a function whose name matches that of the class—the compiler automatically
creates an empty constructor function for you.