问题
In Eclipse 4.5 (Mars) with installed JavaScript Development Tools (JSDT), the default compliance level for ECMAScript is set to ECMAScript 3, which is already very outdated. And the related drop down list to change the compliance level is deactivated, so it's not possible to change the option. Is there a way to change those settings to a newer standard like ECMAScript 5 or ECMAScript 2015?
回答1:
There is no way to use a newer compliance level directly in JSDT, but with a plugin called tern-java you can use ES5 or ES2015 (named before ES6).
I added this plugin via the installation of angular-eclipse. You can find this plugin on Eclipse Marketplace.
回答2:
Eclipse 4.6 (Neon) added support for ECMAScript 2015 syntax and removed the ECMAScript compliance level option from the Preferences dialog.
来源：https://stackoverflow.com/questions/31624174/is-there-a-way-in-eclipse-to-change-the-ecmascript-compliance-level