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Re: Object.defineProperties

Path csiph.com!.POSTED.204-73-239-109.cust.centrio.cz!not-for-mail
From Cezary Tomczyk <cezary.tomczyk@gmail.com>
Newsgroups comp.lang.javascript
Subject Re: Object.defineProperties
Date Fri, 5 May 2017 08:32:55 +0200
Organization csiph.com Internet News Service
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References <oebtq0$2611$1@csiph.com> <objects-20170503082342@ram.dialup.fu-berlin.de> <primitive-types-20170505033844@ram.dialup.fu-berlin.de>
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On 05/05/2017 04:39, Stefan Ram wrote:
> ram@zedat.fu-berlin.de (Stefan Ram) writes:
>> Cezary Tomczyk <cezary.tomczyk@gmail.com> writes:
>>> Native built-in Object.defineProperties method allows me to add
>>> properties to a function as the function is an object.
>> The Web gives:
>> function isObject(val) {
>>    if (val === null) { return false;}
>>    return ( (typeof val === 'function') || (typeof val === 'object') );
>> }
>> . The above might not work with host objects, which might
>> have even other types.
>
>   However, according to Flanagan, a host object may not
>   return »undefined«, »boolean«, »number«, or »string« as
>   its type. So, another way to check whether something is
>   an object might be to check that its type is not one
>   of those.

Yes, but typeof for [] will still returns "object".

One more thing. Regarding:

let a = new String( "abc" );

console.log( Object.prototype.toString.call( a ) );

Object.defineProperty
( a, Symbol.toStringTag, { get: function() { return "Number"; }});

console.log( Object.prototype.toString.call( a ) );

if typing "a instanceof String" then there is "true". So, perhaps 
instanceof is the way of checking the type of object instead of 
Object.prototype.toString.call or typeof or Object.defineProperty[...]

-- 
Cezary Tomczyk
http://www.ctomczyk.pl/
https://www.aslint.org/ - Accessibility validation tool

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Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-03 08:36 +0200
  Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-03 10:14 +0200
    Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-03 10:59 +0200
      Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-03 12:36 +0200
        Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-03 18:47 +0200
          Re: Object.defineProperties Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-05-05 18:18 +0200
    Re: Object.defineProperties Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-05-05 18:14 +0200
      Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-05 19:37 +0200
        Re: Object.defineProperties Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-05-05 20:11 +0200
          Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-06 15:26 +0200
            Re: Object.defineProperties Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-05-06 16:43 +0200
              Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-06 20:23 +0200
                Re: Object.defineProperties Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-05-06 22:21 +0200
                Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-06 23:19 +0200
                Re: Object.defineProperties Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-05-07 02:40 +0200
            Re: Object.defineProperties Stefan Weiss <krewecherl@gmail.com> - 2017-05-06 22:37 +0200
              Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-06 23:05 +0200
                Re: Object.defineProperties Stefan Weiss <krewecherl@gmail.com> - 2017-05-07 00:29 +0200
                Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-07 10:06 +0200
                Re: Object.defineProperties Stefan Weiss <krewecherl@gmail.com> - 2017-05-08 00:50 +0200
                Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-08 13:17 +0200
                Re: Object.defineProperties Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-05-07 02:37 +0200
                Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-07 09:42 +0200
                Re: Object.defineProperties Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-05-07 17:11 +0200
                Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-07 20:08 +0200
        Re: Object.defineProperties Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-05-05 20:59 +0200
          Re: Object.defineProperties John G Harris <niam@jghnorth.org.uk.invalid> - 2017-05-06 10:35 +0100
  Re: Object.defineProperties Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2017-05-05 08:32 +0200
  Re: Object.defineProperties Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-05-05 18:24 +0200

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