Can anyone else use let statements at their Node.js REPL?

Question

Is it possible? It doesn't seem to work in my REPL, neither with nor without --harmony.

What I'd really like to do is use for..of loops, but let seems a simpler thing to troubleshoot and is likely the same reason.

Anyone know anything about the status of these?

Answer 1

$ node --version
v0.10.13

It was a bit cryptic, you'd think just --harmony would work, but you need to add in a use strict somewhere (which you can do at the command line):

$ node --harmony --use-strict
> var letTest = function () {
...   let x = 31;
...   if (true) {
.....     let x = 71;  // different variable
.....     console.log(x);  // 71
.....   }
...   console.log(x);  // 31
... }
undefined
> letTest()
71
31
undefined
> 

Much happy!

However, I tried a simple of comprehension and it didn't work:

[ square(x) for (x of [1,2,3,4,5]) ]

With no luck. It looks like you may have to go past the current stable release to get all the harmony features.