function

Availability

Flash Player 5.

Usage

function functionname ([parameter0, parameter1,...parameterN]){
  statement(s)
}
function ([parameter0, parameter1,...parameterN]){
  statement(s)
}

Parameters

functionname The name of the new function.

parameter An identifier that represents a parameter to pass to the function. These parameters are optional.

statement(s) Any ActionScript instruction you have defined for the body of the function.

Returns

Nothing.

Description

Statement; comprises a set of statements that you define to perform a certain task. You can declare, or define, a function in one location and call, or invoke, it from different scripts in a SWF file. When you define a function, you can also specify parameters for the function. Parameters are placeholders for values on which the function operates. You can pass different parameters to a function each time you call it. This lets you reuse one function in many different situations.

Use the return action in a function's statement(s) to cause a function to return, or generate, a value.

Usage 1: Declares a function with the specified functionname, parameters, and statement(s). When a function is called, the function declaration is invoked. Forward referencing is permitted; within the same Action list, a function may be declared after it is called. A function declaration replaces any prior declaration of the same function. You can use this syntax wherever a statement is permitted.

Usage 2: Creates an anonymous function and returns it. This syntax is used in expressions, and is particularly useful for installing methods in objects.

Example

Usage 1: The following example defines the function sqr, which accepts one parameter and returns the square(x*x) of the parameter. If the function is declared and used in the same script, the function declaration may appear after using the function.

y=sqr(3);

function sqr(x) {
  return x*x;
}

Usage 2: The following function defines a Circle object:

function Circle(radius) {
 this.radius = radius;
}

The following statement defines an anonymous function that calculates the area of a circle and attaches it to the object Circle as a method:

Circle.prototype.area = function () {return Math.PI * this.radius * this.radius}