arrayname.length ==> alternative??

[Marco Snoek]

Hi,

Array('s) like:
customer[1]="John Doe";
items[1][34]="abc";
items[1][422]="aadsfasdf";
customer[2]="Pietje Puk";
items[2][3545]="asdfasdfasdf";
items[2][133]="asdfasdf";
items[2][1155]="sdkk;lj,8i";
etc..

Now: items[2].length is _not_ returning 3 (or 2 whatever point of view :-)..
Any alternative for:
for(anItem in items[2]) { count++; }

??
Thanx in advance,
Marco Snoek

[Michael Winter]

On Sun, 19 Sep 2004 08:45:54 +0200, wrote:

[snip]

customer[2]="Pietje Puk";
items[2][3545]="asdfasdfasdf";
items[2][133]="asdfasdf";
items[2][1155]="sdkk;lj,8i";
etc..

Now: items[2].length is _not_ returning 3 (or 2 whatever point of view
:-)..
No, it won't. Arrays in ECMAScript are sparse arrays: all elements that
aren't explicitly defined between two indicies are given the value,
undefined. So, if you wrote:

var a = [];
a[100] = 'a value';

there would be one explicitly defined value at index 100, and 100
undefined elements before it giving a length of 101.
Any alternative for:
for(anItem in items[2]) { count++; }

The for..in statement seems to be the only way to move through the defined
elements.

[snip]

Mike

--
Michael Winter
Replace ".invalid" with ".uk" to reply by e-mail.

[Lasse Reichstein Nielsen]

"Marco Snoek" <_[mps]@[webmind.nl]_Dont_you_dare_send.spam> writes:
....

items[2][3545]="asdfasdfasdf";
items[2][133]="asdfasdf";
items[2][1155]="sdkk;lj,8i";
etc..

Now: items[2].length is _not_ returning 3 (or 2 whatever point of view :-)..
No, it gives 3546, one larger than the largest index of an element of
the array.
Any alternative for:
for(anItem in items[2]) { count++; }

No, short of keeping track of how many entries have been assigned
yourself.

/L
--
Lasse Reichstein Nielsen - lr*@hotpop.com
DHTML Death Colors: <URL:http://www.infimum.dk/HTML/rasterTriangleDOM.html>
'Faith without judgement merely degrades the spirit divine.'