let expressions, and destructuring assignment.
-version 170 switch on the command line or using the
- Iterators and generators
- Array comprehensions
letstatement (support for
letexpression was dropped in Gecko 41, see bug 1023609).
- const statement
- Destructuring assignment (support for JS1.7 style destructuring for-in was dropped in Gecko 40, see bug 1083498).