Is there a complete definition of the Google App Script Syntax somewhere?

Question

I can't find a complete syntax spec on the developer pages. I'm really wondering if there's an extended for loop ...

https://developers.google.com/apps-script/

I see the Default services, but that isn't defining what control flow syntax we can use. Is it precisely some version of JavaScript?

Answer 1

The GAS is not a precise version of JavaScript. It supports many features of JavaScript 1.8.5 like Object.keys, Object.isExtensible, etc. but on the other hand it does not support the keywords yield and let introduced in JavaScript 1.7. Another features which the GAS supports are the native JSON class and String.trim function introduced in JavaScript 1.8.1. Also the GAS supports the E4X extension.

The GAS documentation is not complete now and many features are discoverable experimentally.