for statement with index and value

Kevin Smith zenparsing at
Tue Jul 14 02:22:08 UTC 2015

Destructuring is here to help:

    for (let [index, value] of [1, 2, 3].entries())
        console.log(index + ": " + value)

The "entries" method returns an iterator of [index, value] pairs.

On Mon, Jul 13, 2015 at 10:13 PM Tingan Ho <tingan87 at> wrote:

> Just following a discussion we had on TypeScript
> In most times, I just need the value in an array, so I use a for..of loop.
> But then, I find out that I need the index too, then I need to rewrite my
> whole for loop expression. Happens all the time for me.
> I have to ask why there doesn't exist a `for statement` where I can get
> the index and value of an array directly? Or for that matter property and
> value of an object?
> `.forEach` is not ideal since you can't break, break to outer loop and
> continue cleanly. Even though you can achieve this with other array
> methods, I don't think they are as productive as a for-statement.
> What I'm suggesting is augmenting the current syntax for `for..of` loops.
> And support an overloading pattern so that we don't need to rewrite the
> whole for loop expression to just to get the index when we already getting
> the value.
> ```
> // overloads
> for (let value, index of values) { ... }
> for (let value of values) { ... }
> ```
> PS. Sorry if this has already discussed. Couldn't find any on Google and
> the page doesn't have any search capabilities.
> _______________________________________________
> es-discuss mailing list
> es-discuss at
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the es-discuss mailing list