Re: input/output parameters

Path	csiph.com!eternal-september.org!reader02.eternal-september.org!.POSTED!not-for-mail
From	Anton Shepelev <anton.txt@gmail.com>
Newsgroups	comp.lang.javascript
Subject	Re: input/output parameters
Date	Sun, 14 Mar 2021 18:51:24 +0300
Organization	A noiseless patient Spider
Lines	51
Message-ID	<20210314185124.0bcbab76d172caf076ac3839@gmail.com> (permalink)
References	<20210313153232.40fa0c8b0adf07d7e807084d@gmail.com> <slrns4plpr.4fd.jon+usenet@raven.unequivocal.eu>
Mime-Version	1.0
Content-Type	text/plain; charset=US-ASCII
Content-Transfer-Encoding	7bit
Injection-Info	reader02.eternal-september.org; posting-host="1d29bea40a1fa08e460c8d6f4bac9272"; logging-data="1216"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18kwc7BGvIbFi8n7wWlzZBguxaDHO2WAJ8="
Cancel-Lock	sha1:aJfIzTSkqisCsSGp/+5A6/4CAZg=
X-Newsreader	Sylpheed 3.7.0 (GTK+ 2.24.30; i686-pc-mingw32)
Xref	csiph.com comp.lang.javascript:39637

Show key headers only | View raw

Jon Ribbens:

> You should probably try and program in the style of the
> language you are using, rather than try and force the
> langauge you are using to work in the style of a different
> language.

What is the JavaScript style of implementing TryParse() and
TryGetValue()?--

   TryParse:    https://docs.microsoft.com/en-us/dotnet/api/system.int32.tryparse
   TryGetValue: https://docs.microsoft.com/en-us/dotnet/api/system.collections.generic.dictionary-2.trygetvalue

The whole point of those and similar functions is their
usefulness as the condition of `if' and `while' statements,
e.g.:

   while( read_next( stream, out element )
   {    // process the element
   }

What alternative(s) does JavaScript propose?

> But you can do this, for example:
>
>   function multiplyAndDivide (data) {
>     data.multiplied = data.a * data.b
>     data.divided = data.a / data.b
>   }
>
>   const values = { a: 2, b: 4 }
>   multiplyAndDivide(values)
>   console.log(values.multiplied, values.divided)

In this example, both calculated values are part of the
result of a successful calcualtion, so it is not analogous
to my case, where I would be forced to return, say, an error
flag, the error text, and a numerical result illogically
grouped together in an object. Your example, on the other
hand, is all right.

The major advantage of output variables is that they let a
function modify the values of the caller's scalar varables
in a transparent way. Passing an object to modify some of
its fields is not as transparent, whereas the need to
"upack" the object's properties back into normal variables
is quite inconvenient.

-- 
()  ascii ribbon campaign -- against html e-mail
/\  http://preview.tinyurl.com/qcy6mjc [archived]

Thread

input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-03-13 15:32 +0300
  Re: input/output parameters Jon Ribbens <jon+usenet@unequivocal.eu> - 2021-03-13 15:16 +0000
    Re: input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-03-14 18:51 +0300
      Re: input/output parameters Jon Ribbens <jon+usenet@unequivocal.eu> - 2021-03-14 16:15 +0000
        Re: input/output parameters John G Harris <niam@jghnorth.org.uk.invalid> - 2021-03-14 18:31 +0000
          Re: input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-03-14 22:27 +0300
            Re: input/output parameters Jon Ribbens <jon+usenet@unequivocal.eu> - 2021-03-14 23:44 +0000
            Re: input/output parameters "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2021-03-15 06:41 -0700
        Re: input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-03-14 22:17 +0300
          Re: input/output parameters Jon Ribbens <jon+usenet@unequivocal.eu> - 2021-03-14 23:28 +0000
          Re: input/output parameters "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2021-03-15 06:39 -0700
      Re: input/output parameters Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-03-14 22:32 +0000
      Re: input/output parameters "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2021-03-15 06:36 -0700
        Re: input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-03-20 14:49 +0300
          Re: input/output parameters "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2021-03-20 11:59 -0700
            Re: input/output parameters "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2021-03-20 13:07 -0700
          Re: input/output parameters John G Harris <niam@jghnorth.org.uk.invalid> - 2021-03-20 19:29 +0000
            Re: input/output parameters Jon Ribbens <jon+usenet@unequivocal.eu> - 2021-03-20 20:35 +0000
  Re: input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-03-15 00:27 +0300
    Re: input/output parameters Jon Ribbens <jon+usenet@unequivocal.eu> - 2021-03-14 23:51 +0000
      Re: input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-03-20 14:56 +0300
        Re: input/output parameters Jon Ribbens <jon+usenet@unequivocal.eu> - 2021-03-20 15:08 +0000
          Re: input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-03-21 15:16 +0300
            Re: input/output parameters "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2021-03-21 08:46 -0700
              Re: input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-04-10 14:54 +0300
        Re: input/output parameters "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2021-03-20 12:05 -0700
          Re: input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-03-21 15:58 +0300
    Re: input/output parameters "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2021-03-15 06:43 -0700
    Re: input/output parameters Silvio <silvio@internet.com> - 2021-03-15 18:01 +0100
      Re: input/output parameters John G Harris <niam@jghnorth.org.uk.invalid> - 2021-03-16 18:06 +0000
        Re: input/output parameters Silvio <silvio@internet.com> - 2021-03-16 23:58 +0100
          Re: input/output parameters John G Harris <niam@jghnorth.org.uk.invalid> - 2021-03-17 19:14 +0000
            Re: input/output parameters Silvio <silvio@internet.com> - 2021-03-17 23:46 +0100
              Re: input/output parameters John G Harris <niam@jghnorth.org.uk.invalid> - 2021-03-18 18:04 +0000
                Re: input/output parameters Silvio <silvio@internet.com> - 2021-03-22 00:39 +0100
                Re: input/output parameters John G Harris <niam@jghnorth.org.uk.invalid> - 2021-03-23 10:44 +0000
                Re: input/output parameters Silvio <silvio@internet.com> - 2021-03-30 00:33 +0200
                Re: input/output parameters John G Harris <niam@jghnorth.org.uk.invalid> - 2021-03-31 19:53 +0100
                Re: input/output parameters Silvio <silvio@internet.com> - 2021-04-01 01:17 +0200
                Re: input/output parameters John G Harris <niam@jghnorth.org.uk.invalid> - 2021-04-01 18:02 +0100
      Re: input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-03-20 15:50 +0300
        Re: input/output parameters John G Harris <niam@jghnorth.org.uk.invalid> - 2021-03-20 18:52 +0000
          Re: input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-03-21 17:35 +0300
            Re: input/output parameters "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2021-03-21 08:50 -0700
              Re: input/output parameters Anton Shepelev <anton.txt@gmail.com> - 2021-03-21 19:31 +0300
            Re: input/output parameters John G Harris <niam@jghnorth.org.uk.invalid> - 2021-03-21 19:27 +0000
        Re: input/output parameters "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2021-03-20 13:02 -0700
  Re: input/output parameters Postiljon Petskin <yyyyyyyyyyyywwwww@zohomail.eu> - 2023-04-22 08:47 -0700

csiph-web