javascript - obj的长度为1-JavaScript

我正在尝试根据用户插入的邮政编码自动填充城市和州的值。我无法将输入的邮政编码与json对象中可用的邮政编码进行比较。 obj length的值为1，必须为3。

var text = '{"zipcodes":[' +
'{"zip":"22031","city":"Fairfax" ,"State":"VA" },' +
'{"zip":"22032","city":"AshBurn" ,"State":"VA" },' +
'{"zip":"22033","city":"Tysons" ,"State":"VA" }]}';

var obj = JSON.parse(text);
var n = Object.keys(obj).length;

for(i=0; i<=n; i++){

    if(obj.zipcodes[i].zip.parseInt() == zipcodes.parseInt()){

        document.getElementById("city").value = obj.zipcodes[i].city;
        document.getElementById("state").value = obj.zipcodes[i].State;

    }
}

最佳答案

解析后的对象变为：

{
  "zipcodes":[
    {"zip":"22031","city":"Fairfax" ,"State":"VA" },
    {"zip":"22032","city":"AshBurn" ,"State":"VA" },
    {"zip":"22033","city":"Tysons" ,"State":"VA" }]}
  ]
};

因此，对象的密钥数为1，即邮政编码。如果您想计算邮政编码，

用这个：

var obj = JSON.parse(text);
var n = obj.zipcodes.length;

关于javascript - obj的长度为1-JavaScript，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/33195888/