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Re: Create a multi-dimensional array

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2011-11-23 13:04, Archos wrote:

> To create a two dimensional array I use:
>
>    var a4 = new Array(3); for (i=0; i<3; i++) a4[i]=new Array(5);
>
> In pseudoce: a4 = [3][5]

The value of a4 is an array, where the elements are arrays. Calling it a 
two-dimensional array probably confuses rather than helps. The notation 
[3][5] is not meaningful as such.

> Then, to create a 3 dim. array, I tried this one:
>
>    var a5 = new Array(2); for (i=0; i<2; i++) a5[i]=new Array(2); for
> (i=0; i<2; i++) a5[i]=new Array(2);

I don't see what you regard as three-dimensional here, and I don't 
understand why you have the same 'for' loop twice.

>>>> console.log(a5[1][0])
> undefined

Naturally, because no value has been assigned to it. You have created an 
array with two elements, each of which is an array of two elements, each 
of which is initially undefined. Try setting e.g.
a5[1] = ['Hello world', 42]
or
a5[1][0] = 'foobar'
and you'll see that a5 works fine as a simulation of a two-dimensional 
array.

-- 
Yucca, http://www.cs.tut.fi/~jkorpela/

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Create a multi-dimensional array Archos <raul.san@sent.com> - 2011-11-23 03:04 -0800
  Re: Create a multi-dimensional array "Jukka K. Korpela" <jkorpela@cs.tut.fi> - 2011-11-23 13:41 +0200
    Re: Create a multi-dimensional array John G Harris <john@nospam.demon.co.uk> - 2011-11-23 16:41 +0000
    Re: Create a multi-dimensional array Dr J R Stockton <reply1147@merlyn.demon.co.uk> - 2011-11-24 18:42 +0000
      Re: Create a multi-dimensional array "Jukka K. Korpela" <jkorpela@cs.tut.fi> - 2011-11-25 01:53 +0200
        Re: Create a multi-dimensional array Gene Wirchenko <genew@ocis.net> - 2011-11-24 17:15 -0800
  Re: Create a multi-dimensional array Erwin Moller <Since_humans_read_this_I_am_spammed_too_much@spamyourself.com> - 2011-11-23 12:46 +0100
    Re: Create a multi-dimensional array Archos <raul.san@sent.com> - 2011-11-23 06:11 -0800
  Re: Create a multi-dimensional array Denis McMahon <denismfmcmahon@gmail.com> - 2011-11-23 18:34 +0000
    Re: Create a multi-dimensional array Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-11-23 21:33 +0100

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