[code]遍历Map并按照key排序

var map = {};
map['userid']= '123456';
map['SCYver']= '0.1';
map['SCYuserid']= '087654'; 
map['SCYtimestamp']= '123456789';

var arr = new Array(),i = 0;
for (var key in map) {
	if (map.hasOwnProperty(key)) {		
		arr[i++]=key;
	}
}
var arr2 = arr.sort();
alert(arr2.length);
var signStr='';
for (var j = 0; j < arr2.length; j++) {
	signStr+=arr2[j]+map[arr2[j]];
}
console.log(signStr);