I\'ve been searching for an answer but I\'m only getting results regarding the Google maps API. I\'m trying to use a map in JavaScript to map an integer to a string. Everyth
Map is now in Chrome version 38 (beta as of 29-Aug-2014), which means it will get to stable very shortly. If you have 38, no need to enable experimental features.
Some ES harmony features, including Map(), did already exist in Chrome at the end of 2011. It's just disabled by default.
To enable the feature, visit chrome://flags/, and enable "Enable experimental JavaScript". Then restart the browser and enjoy the new features.

An alternative method is to pass the --js-flags=--harmony flag on the command line. For instance:
chromium --js-flags=--harmony
chrome.exe --jsflags=--harmony
Why not use a simple array?
var NameMap;
var DistanceMap;
function FillMaps(){
NameMap = new Array();
DistanceMap = new Array();
NameMap[01]="Araba/Álava";
}
function CheckName(_field){
var value = document.getElementsByName(_field.name).item(0).value;
var location = value.charAt(0) + value.charAt(1);
var result = NameMap[parseInt(location)];
if(result == undefined){
result = "Unknown";
}
document.getElementById('loc').innerHTML = result;
}
"Danger! Experimental technology!"
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map
Its possible the code here can implement Map for Chrome, but I've not tried:
http://wiki.ecmascript.org/doku.php?id=harmony:simple_maps_and_sets