"use strict" VS setTimeout

Andrea Giammarchi andrea.giammarchi at gmail.com
Sun Sep 7 11:07:53 PDT 2014


Yes Axel, that's how it works, this will show undefined indeed all over

```js
(function () {
  'use strict';
  function g() {
    console.log(this);
  }
  g(); // undefined
  setTimeout(function () {
    g(); // undefined
  }, 0);
}());
```

or testing other use strict restrictions:

```js
(function () {
  'use strict';
  setTimeout(function () {
    argument.callee
  }, 0);
}());
```

The strict behavior is preserved, it's not an opt-out, but the invoked
function within setTimeout has the global context regardless it has been
defined under the strict directive + regardless it defines itself as strict.

Basically if you feel secure about "use strict" here you have a case that
shows you shouldn't ... making one point of strict directive kinda
broken/pointless.

Regards






On Sun, Sep 7, 2014 at 7:02 PM, Axel Rauschmayer <axel at rauschma.de> wrote:

> On Sep 7, 2014, at 19:47 , Mark S. Miller <erights at google.com> wrote:
>
> On Sun, Sep 7, 2014 at 10:36 AM, Mathias Bynens <mathiasb at opera.com>
> wrote:
>
>> On Sun, Sep 7, 2014 at 7:29 PM, Andrea Giammarchi
>> <andrea.giammarchi at gmail.com> wrote:
>> > This looks like a potential problem when possible passed methods are not
>> > bound + it looks inconsistent with *"use strict"* expectations.
>>
>
> Yes. This looks like a typical screwup. Thanks for pointing it out.
>
>
> Interesting. Follow-up question: isn’t strictness propagated lexically?
> That is, shouldn’t the parameter of `setTimeout()` be strict even without
> being explicitly declared as such?
>
> --
> Dr. Axel Rauschmayer
> axel at rauschma.de
> rauschma.de
>
>
>
>
> _______________________________________________
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> es-discuss at mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
>
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