Understanding the ActionScript Language > Using ActionScript syntax > Dot syntax

 

Dot syntax

In ActionScript, a dot (.) is used to indicate the properties or methods related to an object or movie clip. It is also used to identify the target path to a movie clip, variable, function, or object. A dot syntax expression begins with the name of the object or movie clip followed by a dot, and ends with the element you want to specify.

For example, the _x movie clip property indicates a movie clip's x axis position on the Stage. The expression ballMC._x refers to the _x property of the movie clip instance ballMC.

As another example, submit is a variable set in the form movie clip, which is nested inside the movie clip shoppingCart. The expression shoppingCart.form.submit = true sets the submit variable of the instance form to true.

Expressing a method of an object or movie clip follows the same pattern. For example, the play method of the ballMC instance moves the playhead in the Timeline of ballMC, as in the following statement:

ballMC.play();

Dot syntax also uses two special aliases, _root and _parent. The alias _root refers to the main Timeline. You can use the _root alias to create an absolute target path. For example, the following statement calls the function buildGameBoard in the movie clip functions on the main Timeline:

_root.functions.buildGameBoard();

You can use the alias _parent to refer to a movie clip in which the current movie clip is nested. You can also use _parent to create a relative target path. For example, if the movie clip dog is nested inside the movie clip animal, the following statement on the instance dog tells animal to stop:

_parent.stop();

See Working with Movie Clips and Buttons.