var hash = new Array();
hash['year'] = 2005;
hash['month'] = 12;
hash['date'] = 14;
var str = '';
for ( key in hash ){
str += key + ":" + hash[key] + "\n";
}
alert(str);
追記
JavaScriptはObjectで連想配列を利用可能.var hash = new Object();
Reference
にっき - 2005-12-15http://bigfield.ddo.jp/diary/20051215.html#p03