Javascript looping only through defined properties of array. How?

Posted by Beck on Stack Overflow See other posts from Stack Overflow or by Beck
Published on 2010-06-12T13:47:17Z Indexed on 2010/06/12 13:52 UTC
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JavaScript

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loops

For example if i'm keeping array of references via id like that:

if(typeof channel_boards[misc.channel_id] == 'undefined') {

    channel_boards[misc.channel_id] = $('<div class="channel" channel_id="'+misc.channel_id+'"></div>').appendTo('#board');
}

And then i'm looping through array to find required reference. I'm looping through undefined properties as well. Is it possible to loop only through defined properties?

for(i=0;i<channel_boards.length;i++)
{
    if(channel_boards[i] != undefined)
    {
        if(channel_boards[i].attr('channel_id') != visible) {channel_boards[i].addClass('hidden_board');}
        else {channel_boards[i].removeClass('hidden_board');}       
    }
}

Maybe i should change the way i'm storing references? Via object for example, but how i'll be able to find proper reference via id number.

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