解析map：
var obj = {
"a": 1,
"b": 2,
"c": 3
};
for (var prop in obj) {
if (obj.hasOwnProperty(prop)) {
// or if (Object.prototype.hasOwnProperty.call(obj,prop)) for safety...
alert("prop: " + prop + " value: " + obj[prop])
}
}
双重map解析：
var msg = "";
for(var key in Pin) {
for(var i in Pin[key]){
msg+=i+": "+Pin[key][i]+"\n";
}
}
alert(msg);
