Collections in javascript

[Eitan]

Hello,

I am looking for a collection object in javascript (like dictionary in VB).

Give me some sample code ,please.

Thanks :)

[David Dorward]

Re: Collections in javascript

Eitan wrote:
[color=blue]
> I am looking for a collection object in javascript (like dictionary in
> VB).[/color]

var foo = new Array();
foo['bar'] = 'baz';


--
David Dorward <http://blog.dorward.me .uk/> <http://dorward.me.uk/>
Home is where the ~/.bashrc is

[Grant Wagner]

Re: Collections in javascript

David Dorward wrote:
[color=blue]
> Eitan wrote:
>[color=green]
> > I am looking for a collection object in javascript (like dictionary in
> > VB).[/color]
>
> var foo = new Array();
> foo['bar'] = 'baz';[/color]

Don't use an Array, because if you attempt to iterate the properties of the
object later, you'll end up with properties called 'pop', 'push', 'length',
etc

var foo = new Object(); // { }
foo['bar'] = 'baz';

Even with this, there are a number of enumerable properties you'll uncover
using -for (var x in foo)-.

If you actually need a Collection object you'll have to roll your own. For
example, the following code give you a Collection which guarantees that values
are retrieved in the order they were added:

<script type="text/javascript">
function Collection() {
var collection = {};
var order = [];

this.add = function(proper ty, value) {
if (!this.exists(p roperty)) {
collection[property] = value;
order.push(prop erty);
}
}
this.remove = function(proper ty) {
collection[property] = null;
var ii = order.length;
while (ii-- > 0) {
if (order[ii] == property) {
order[ii] = null;
break;
}
}
}
this.toString = function() {
var output = [];
for (var ii = 0; ii < order.length; ++ii) {
if (order[ii] != null) {
output.push(col lection[order[ii]]);
}
}
return output;
}
this.getKeys = function() {
var keys = [];
for (var ii = 0; ii < order.length; ++ii) {
if (order[ii] != null) {
keys.push(order[ii]);
}
}
return keys;
}
this.update = function(proper ty, value) {
if (value != null) {
collection[property] = value;
}
var ii = order.length;
while (ii-- > 0) {
if (order[ii] == property) {
order[ii] = null;
order.push(prop erty);
break;
}
}
}
this.exists = function(proper ty) {
return collection[property] != null;
}
}

var myCollection = new Collection();
myCollection.ad d("first", "Adam");
myCollection.ad d("second", "Eve");
myCollection.ad d("third", "Cane");
myCollection.ad d("fourth", "Abel");
myCollection.re move("second");
myCollection.ad d("fifth", "Noah");
alert(myCollect ion.toString()) ;
alert(myCollect ion.getKeys());
myCollection.up date("first");
alert(myCollect ion.toString()) ;
alert(myCollect ion.exists("thi rd"));
alert(myCollect ion.exists("som ething"));
</script>

--
Grant Wagner <gwagner@agrico reunited.com>
comp.lang.javas cript FAQ - http://jibbering.com/faq

[Steve van Dongen [MSFT]]

Re: Collections in javascript

"Eitan" <no_spam_please @nospam.com> wrote:
[color=blue]
>Hello,
>
>I am looking for a collection object in javascript (like dictionary in VB).
>
>Give me some sample code ,please.
>
>Thanks :)[/color]

If you are only interested in MS JScript you can use the dictionary
object.

http://msdn.microsoft.com/library/en-us/script56/html/jsobjDictionary.asp

Regards,
Steve
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