do while scope

Caitlin Potter caitpotter88 at gmail.com
Fri Apr 17 15:24:35 UTC 2015


Well, there's a lot of precedent I'm languages for it (the while condition) to not be a part of the block scope. So from that prospective it's unsurprising, though it may surprise developers accustomed to variable hosting

> On Apr 17, 2015, at 11:18 AM, Glen Huang <curvedmark at gmail.com> wrote:
> 
> Not sure about others, but i assume the condition part and statement part in a control construct live in the same scope.
> 
> That's why you can do `for (let a = 1; a < 2; a++) a;`. And `if (let a = 1) a;` maybe in es7?
> 
> Why that's not the case for "do while"? Is my mental model wrong?
> 
>> On Apr 17, 2015, at 11:10 PM, Caitlin Potter <caitpotter88 at gmail.com> wrote:
>> 
>> Is there a language where lexically scoped variables declared in a block are accessible outside of that block? Java, C, C#, rust, Python, etc, will not let you do this. I’m not sure this is a gotcha for most software developers
>> 
>>> On Apr 17, 2015, at 10:57 AM, Glen Huang <curvedmark at gmail.com> wrote:
>>> 
>>> ```js
>>> do {
>>> let a = 1;
>>> } while (a);
>>> ```
>>> is "a" undefined in the while condition? This seems like a gotcha.
>>> 
>>> 
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