Adobe After Effects CS5 Visual Effects and Compositing Studio Techniques

JavaScript Guide

Dan Ebberts

JavaScript is the glue that binds expressions together. If you want to get beyond creating expressions with the pick whip, you need to know how to use JavaScript. The After Effects expressions language is based on only a subset of JavaScript, however, which means there’s a lot about JavaScript that you don’t need to learn. To help you separate the vital from the unnecessary, this guide focuses on the core elements of JavaScript that are essential to master if you really want to understand expressions.

Variables

In multiline expressions, you sometimes need to save an intermediate result for later use in the expression. In such cases, you need to define a variable. A variable is nothing more than a temporary storage ...