Chrome处置JSON数据时的特殊之处

有JSON字符串如下：

?

var cities = {
	"2":
		{
			"id":"2","name":"shanghai"
		},
	"1":
		{
			"id":"1","name":"beijing"
		},
	"4":
		{
			"id":"4","name":"shenzhen"
		},
	"3":
		{
			"id":"3","name":"xianggang"
		}
	};

?

?遍历该JSON对象，将其顺序打印出来，Chrome会和其他浏览器得到不同的结果。

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<script>
var cities = {
	"2":
		{
			"id":"2","name":"shanghai"
		},
	"1":
		{
			"id":"1","name":"beijing"
		},
	"4":
		{
			"id":"4","name":"shenzhen"
		},
	"3":
		{
			"id":"3","name":"xianggang"
		}
	};

var row;
for(i in cities)
{
	row = "ID:"+cities[i].id+",Name:"+cities[i].name+"<br />";
	document.write(row);
}
</script>

?

?IE、Firefox及Safari得到结果均为：

?但Chrome的运行结果为：

?

?原因在于这个JSON对象下标是数字，Chrome根据其下标由小到大对对象个元素重新排了序。

?若把下标改为字符或者将下标删除：

?

<script>
/*
var cities = {
	"b":
		{
			"id":"2","name":"shanghai"
		},
	"a":
		{
			"id":"1","name":"beijing"
		},
	"d":
		{
			"id":"4","name":"shenzhen"
		},
	"c":
		{
			"id":"3","name":"xianggang"
		}
	};
*/
var cities = [
	{
		"id":"2","name":"shanghai"
	},
	{
		"id":"1","name":"beijing"
	},
	{
		"id":"4","name":"shenzhen"
	},
	{
		"id":"3","name":"xianggang"
	}
];

var row;
for(i in cities)
{
	row = "ID:"+cities[i].id+",Name:"+cities[i].name+"<br />";
	document.write(row);
}
</script>

?则各浏览器下结果均为：

?

?