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From: Thomas 'PointedEars' Lahn <PointedEars@web.de>
Newsgroups: comp.lang.javascript
Subject: Re: check for obj nested prop
Date: Tue, 12 May 2020 09:28:31 +0200
Organization: PointedEars Software (PES)
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Ben Bacarisse wrote:

> Thomas 'PointedEars' Lahn <PointedEars@web.de> writes:
>> Ben Bacarisse wrote:
>>> Andrew Poulos <ap_prog@hotmail.com> writes:
>>>> so I end up doing
>>>>
>>>> if (a && a.b && a.b.c && a.b.c.d)
>>> <cut>
>>>> Is there a way to get the check value of an object's nested property
>>>> without first having to test for all the ascendant properties?
>>> 
>>>   if (try {obj.a.b.c.d} catch {})
>>> 
>>> might do what you want.
>>
>> This is *obviously* syntactically invalid;
> 
> Yes, wishful thinking.  You'd need a function call and a return:
> 
>   if ( (()=>{ try {return obj.a.b.c.d} catch {} })() ) ...
> 
> which makes it rather clumsy.

It is not only clumsy, it is also not safe (and this particular syntax
is also not backwards-compatible; the compatible syntax is even more 
clumsy); see my *detailed* follow-up.
 
-- 
PointedEars
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