Understanding the ActionScript Language > About custom objects > Creating a custom object |  |

Creating a custom object

To create a custom object, you define a constructor function. A constructor function is always given the same name as the type of object it creates. You can use the keyword `this` inside the body of the constructor function to refer to the object that the constructor creates; when you call a constructor function, Flash passes it `this` as a hidden parameter. For example, the following is a constructor function that creates a circle with the property `radius`:

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

After you define the constructor function you must create a new instance of the object. Use the `new` operator before the name of the constructor function and assign the new instance a variable name. For example, the following code uses the `new` operator to create a new Circle object with a radius of 5, and assigns it to the variable `myCircle`:

    myCircle = new Circle(5);

Note: An object has the same scope as the variable to which it is assigned. See Scoping a variable.

For more information about creating and using objects, see About built-in objects.