After Effects Expressions differences for JavaScript.

[Walter Soyka]

The Javascript implementation seems quite extensive. Don’t just learn Javascript, though — learning the Ae side is critical for writing expressions. Here are a couple of good resources:

https://helpx.adobe.com/after-effects/using/expression-basics.html

https://helpx.adobe.com/after-effects/using/expression-language-reference.html

https://helpx.adobe.com/after-effects/using/expression-examples.html

https://www.motionscript.com/

Walter Soyka
Designer & Mad Scientist at Keen Live [link]
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
@keenlive   |   RenderBreak [blog]   |   Profile [LinkedIn]

[Tiago Cav]

Thank You!

[Darby Edelen]

As I recall After Effects expressions use ECMAscript which (in addition to being ugly) is the standards controlled implementation of JavaScript. It’s possible that ECMAscript does not implement all of the features of JavaScript but I haven’t run into any obvious differences.

As far as After Effects is concerned there are lots of AE specific objects implemented which I believe Walter has covered admirably. Dan Ebberts’ site (https://www.motionscript.com) is a great source for AE specific paradigms.

The only other thing to keep in mind is that an AE expression evaluates fresh on every frame. There is no knowledge of what happened on previous frames (the variables are re-initialized) unless you explicitly code the expression that way.

Darby Edelen

[Tiago Cav]

Thank You!
I learn a little of expressions, because i study JavaScript in CodeCademy.com