define an array in JavaScript

Question

how would you define an array in JavaScript like the one below and retrieve values by doing a search for country and gets the list of region.

region['US'] = {'Region 1': 'East', 'Region 2': 'West'}

You have listed an object, not an array. In JavaScript, arrays with string keys are always objects. — Lix, Apr 30 '13 at 17:53
[JavaScript doesn't have associative arrays, but you can create an abstract object](http://stackoverflow.com/q/1098040/901048) which basically behaves the same way. — Blazemonger, Apr 30 '13 at 17:54
You would need to use JSON and JSON's dot notation to retrieve data. — Scott Sword, Apr 30 '13 at 17:54
@Lix: All keys in JavaScript are strings... just to be clear. All arrays are always objects. — , Apr 30 '13 at 17:55
@squint if it is an `Array` then the `keys` are just the index in the array. That's what he is talking about. — Daniel Moses, Apr 30 '13 at 17:56
@squ - `var a = ['foo','bar']; var index=0; index++; console.log(a[index])`. Or am I missing something? — Lix, Apr 30 '13 at 17:56
@Lix Only that `index` is converted to a string when used in the `[]` operator. Using `"0"` would work just the same. — , Apr 30 '13 at 17:57

score 1 · Answer 1 · answered Apr 30 '13 at 17:55

1

You want an object, not an array. Objects have string keys, arrays have numeric keys only.

var region = {
  US: {'Region 1': 'East', 'Region 2': 'West'},
  UK: {'Region 1': 'East', 'Region 2': 'West'}

}

then get it with

region['US']

or

region.US

answered Apr 30 '13 at 17:55

Ben McCormick

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score 0 · Accepted Answer · answered Apr 30 '13 at 17:59

If we declare specific classes for the Country and the Region, this should work:

var Region = function(data) {
 var self = this;
 self.name = data.name || "";
}

var Country = function(data) {
 var self = this;
 self.name = data.name || "";
 self.regions = new Array();
}

var countries = {};
countries["US"] = new Country({ "name" : "US" });
countries["US"].regions.push(new Region({ "name" : "Region 1"}));
countries["US"].regions.push(new Region({ "name" : "Region 2"}));

define an array in JavaScript

2 Answers2