Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.javascript > #24513

Re: Difference between two arrays

Show all headers | View raw

"Michael Haufe (TNO)" <tno@thenewobjective.com> wrote on 31 mei 2014 in
comp.lang.javascript: 

> On Wednesday, May 28, 2014 12:22:39 PM UTC-5, Dr J R Stockton wrote:
> [...]
>> 
>> Create a third array which contains the first array once and the second
>> array twice.  Then use sort() to get a fourth array from the third.
>> Then do a linear scan of the fourth array looking for consecutive equal
>> elements.  Singlets occur in only the first array, doublets only in the
>> second, and triplets occur in both.  You can then store copies of the
>> elements according to multiplicity in three more arrays.
>> Of course, you do not copy elements; you only make new pointers to
>> them. The method should be reasonably efficient, and extends to
>> comparing more than two arrays.
> 
> - JavaScript sort is an in-place sort, so I don't know where this 4th
> array is coming from. - Would you mind qualifying "reasonably
> efficient"? I'm not convinced of this using what I think is your
> approach, especially as more than two arrays are used. 

How simple would it be to have 
two single field database tables
and select all records in MyTable1 
that are not in MyTable2,
using: 

sql = "SELECT MyField FROM MyTable1 
WHERE NOT (MyField = ANY (SELECT MyField FROM MyTable2) );"

[Access/Jet engine, not tested.]

Can this be done clientside using webSQL?

<http://html5doctor.com/introducing-web-sql-databases/>

-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

Back to comp.lang.javascript | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Difference between two arrays Andrew Poulos <ap_prog@hotmail.com> - 2014-05-27 11:55 +1000
  Re: Difference between two arrays Denis McMahon <denismfmcmahon@gmail.com> - 2014-05-27 05:58 +0000
  Re: Difference between two arrays John C <rescattered@gmail.com> - 2014-05-27 03:34 -0700
    Re: Difference between two arrays Spamless <Spamless@Nil.nil> - 2014-05-31 06:35 -0500
      Re: Difference between two arrays Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-05-31 14:57 +0200
        Re: Difference between two arrays Spamless <Spamless@Nil.nil> - 2014-06-01 03:43 -0500
          Re: Difference between two arrays Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-06-01 14:01 +0200
            Re: Difference between two arrays Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-06-01 16:53 +0200
  Re: Difference between two arrays Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-05-27 13:41 +0100
    Re: Difference between two arrays Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-05-27 17:41 +0200
    Re: Difference between two arrays Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-05-27 17:49 +0200
      Re: Difference between two arrays Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-05-27 17:34 +0100
        Re: Difference between two arrays Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-05-27 19:33 +0200
          Re: Difference between two arrays Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-05-27 20:03 +0100
    Re: Difference between two arrays Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-05-27 17:16 +0100
      Re: Difference between two arrays Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-05-27 19:29 +0200
  Re: Difference between two arrays Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-05-27 17:21 +0200
  Re: Difference between two arrays Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-05-28 18:22 +0100
    Re: Difference between two arrays Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-05-30 22:23 +0100
    Re: Difference between two arrays "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-05-31 14:59 -0700
      Re: Difference between two arrays "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-06-01 00:50 +0200
        Re: Difference between two arrays "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-05-31 16:17 -0700
          Re: Difference between two arrays "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-06-01 10:49 +0200
            Re: Difference between two arrays "Michael Haufe (TNO)" <tno@thenewobjective.com> - 2014-06-01 13:37 -0700
      Re: Difference between two arrays Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-06-01 18:56 +0100

csiph-web