Anything beyond the last variable shouldn't be returned - anything else would be exceedingly unexpected. Note that in terms of completions, they all currently return `undefined` when you `eval` them, but for `if (let ...)` and `while (let ...)`, I would expect that it'd work similarly to sequence expressions.
On Tue, Aug 21, 2018 at 12:08 Ali Rahbari <[email protected]> wrote: > The problem with let, const or var is you can define multiple variable > after them, and it's ambiguous which one must be returned from the > expression. But like comma expression which would return the last part as a > result, the let and const also should return the last assignment as the > result so it can be used inside parentheses > > (let a = 1, b = 2) === 2 > > A common type of code in JS is searching for element and do something with > them: > > let e1 = document.getElementById('id1'); > if (e1) this.AppendChild(e); > > let e2 = document.getElementById('id2'); > if (e2) this.AppendChild(e); > > This pattern can really help encapsulation and readability; > > if (let e = document.getElementById('id1')) this.AppendChild(e); > if (let e = document.getElementById('id2')) this.AppendChild(e); > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss >
_______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
