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Re: not "autovivification", but ...?

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On Tuesday, May 31, 2016 at 7:11:39 AM UTC-5, Christoph M. Becker wrote:
> On 31.05.2016 at 13:51, Stefan Ram wrote:
> 
> > (Stefan Ram) writes:
> >> "use strict"; this.b = 1;
> > 
> >   And I wonder, why in strict mode in the outmost scope, when
> > 
> > b = 1
> > 
> >   is forbidden (given that »this.b« does not exist)
> > 
> > this.b = 1
> > 
> >   is allowed. What is the rationale for allowing it with »this.«?
> 
> `this` is not special in this regard;  you can assign to undefined
> properties of *any* object.

Most, not any. For example: [1]

> Also consider that accessing undefined properties of an object yield
> `undefined` (but not an error), so it appears to be logical to allow
> assigning another value to such undefined properties.

That does not follow. Ex:

//assume this function is defined in a 3rd party library
function getSomeObject(){
  return Object.seal({
    hello: "world"
  })
}

//in your code somewhere:
var someObject = getSomeObject()

typeof someObject.hello // string

typeof someObject.hola // undefined

someObject.hola = "mundo"

typeof someObject.hola // undefined


[1] <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/seal>

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Re: not "autovivification", but ...? "Christoph M. Becker" <cmbecker69@arcor.de> - 2016-05-31 14:11 +0200
  Re: not "autovivification", but ...? "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2016-06-01 07:51 -0700
    Re: not "autovivification", but ...? "Christoph M. Becker" <cmbecker69@arcor.de> - 2016-06-01 18:46 +0200

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