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Re: 'pushing' vs direct array assignment ?

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Rob said:

In order to determine a preference for one method or another, it is 
important to establish the criteria for evaluation. Some that might apply 
(in approximate order of importance) are:

1. Unintended side effects: iterating over an array by index may create 
undefined properties, but if you are creating a contiguous list from zero 
then it doesn't matter.

2. Support in likely host environments: very old browsers don't support 
Array.prototype.push, so if you need to support those it's better to use 
direct assignment (or add a push method if feature detection shows it's 
missing, which may be another question). If you use direct assignment, you 
never need to worry. But there must be very few browsers on the web that 
don't have push.

3. Performance: as has been noted, this goes both ways. For 1,500 items, I 
suspect it won't make much difference on a modern computer, but might be 
significant in the types of environments where support for push is more 
likely to be lacking.

4. Maintainability (code clarity): I don't think there are any issues here 
with one approach or the other.

5. Number of characters to type: direct assignment saves 3 characters, not 
worth dying in a ditch over (IMHO of course).

So on balance, for code expected to be widely used on the web, I'd go with 
direct assignment, but be happy with push if it was used.

Applying the above analysis to your context might give a different result.

> or, is there another preferred way to do this quickly ?

Depending on your target environment, JavaScript™ 1.7 (released in October 
2006 with Firefox 2) introduced iterators and generators[1]. But that 
approach doesn't get a very high score for the support criterion if you need 
to work with environments other than those compliant with JavaScript™ 1.7.

1. 
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Iterators_and_Generators


Hi Rob:

    The above gives me much more to 'chew on' and puzzle over.  Also, the 
link above on 'Iterators ...' will provide substance for this evening's 
reading  -- The .next() function is completely new to me.

Thank you.

-Mel 

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'pushing' vs direct array assignment ? "Mel Smith" <med_cutout_syntel@aol.com> - 2013-06-03 13:59 -0600
  Re: 'pushing' vs direct array assignment ? Scott Sauyet <scott.sauyet@gmail.com> - 2013-06-03 13:39 -0700
    Re: 'pushing' vs direct array assignment ? "Mel Smith" <med_cutout_syntel@aol.com> - 2013-06-03 14:46 -0600
    Re: 'pushing' vs direct array assignment ? Stefan Weiss <krewecherl@gmail.com> - 2013-06-04 02:07 +0200
      Re: 'pushing' vs direct array assignment ? "Mel Smith" <med_cutout_syntel@aol.com> - 2013-06-03 18:40 -0600
        Re: 'pushing' vs direct array assignment ? "Mel Smith" <med_cutout_syntel@aol.com> - 2013-06-03 20:38 -0600
        Re: 'pushing' vs direct array assignment ? Martin Leese <please@see.Web.for.e-mail.INVALID> - 2013-06-04 09:11 -0600
          Re: 'pushing' vs direct array assignment ? "Mel Smith" <med_cutout_syntel@aol.com> - 2013-06-04 12:47 -0600
            Re: 'pushing' vs direct array assignment ? Stefan Weiss <krewecherl@gmail.com> - 2013-06-04 22:44 +0200
              Re: 'pushing' vs direct array assignment ? "Mel Smith" <med_cutout_syntel@aol.com> - 2013-06-04 16:02 -0600
            Re: 'pushing' vs direct array assignment ? Martin Leese <please@see.Web.for.e-mail.INVALID> - 2013-06-04 20:24 -0600
              Re: 'pushing' vs direct array assignment ? Gregor Kofler <usenet@gregorkofler.com> - 2013-06-05 14:50 +0200
                Re: 'pushing' vs direct array assignment ? Martin Leese <please@see.Web.for.e-mail.INVALID> - 2013-06-05 22:38 -0600
              Re: 'pushing' vs direct array assignment ? Tim Slattery <Slattery_T@bls.gov> - 2013-06-05 08:51 -0400
                OT: Accept-Encoding (was: 'pushing' vs direct array assignment ?) Christoph Becker <cmbecker69@gmx.de> - 2013-06-05 15:23 +0200
  Re: 'pushing' vs direct array assignment ? RobG <rgqld@iinet.net.au> - 2013-06-05 18:12 -0700
    Re: 'pushing' vs direct array assignment ? "Mel Smith" <med_cutout_syntel@aol.com> - 2013-06-06 08:54 -0600

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