如何在Jquery中循环对象？

I am getting TypeError: field[i] is undefined from this:

我得到TypeError：field [i]未定义：

function ObserverFetch() {

               $.ajax({
                   type: "POST",
                   url: "Observer.aspx/ObserverFetch",
                   data: JSON.stringify({ id: "" }),
                   contentType: "application/json; charset=utf-8",
                   dataType: "json",
                   async: true,
                   success: function (data, status) {

                       $.each(data, function (i, field) {

                           alert(field[i].BidderName);
                           //$('#dvBids').text(field);
                           //$("#gvDetails").append("<tr><td>" + field.SrNo + "</td><td>" + field.BidderName + "</td><td>" + field.BidAmt + "</td></tr>");
                       });                     
                   },
                   failure: function (data) {
                       alert(data.d);
                   },
                   error: function (data) {
                       alert(data.d);
                   }
               });
       }

This is what I get in field

这就是我在现场得到的

[{"SrNo":4,"BidderName":"faisal","BidAmt":6000000.0000,"BidDate":"\/Date(1430199508063)\/"},{"SrNo":3,"BidderName":"arbaaz jalil","BidAmt":5000010.0000,"BidDate":"\/Date(1430199494083)\/"},{"SrNo":2,"BidderName":"arbaaz","BidAmt":500000.0000,"BidDate":"\/Date(1430199483530)\/"},{"SrNo":1,"BidderName":"shekhar1","BidAmt":5000.0000,"BidDate":"\/Date(1430199394957)\/"}]

$('#dvBids').text(JSON.stringify(data)); gives me :

$（ '＃dvBids'）文本（JSON.stringify（数据））。给我：

{"d":"[{\"SrNo\":4,\"BidderName\":\"faisal\",\"BidAmt\":6000000.0000,\"BidDate\":\"\\/Date(1430199508063)\\/\"},{\"SrNo\":3,\"BidderName\":\"arbaaz jalil\",\"BidAmt\":5000010.0000,\"BidDate\":\"\\/Date(1430199494083)\\/\"},{\"SrNo\":2,\"BidderName\":\"arbaaz\",\"BidAmt\":500000.0000,\"BidDate\":\"\\/Date(1430199483530)\\/\"},{\"SrNo\":1,\"BidderName\":\"shekhar1\",\"BidAmt\":5000.0000,\"BidDate\":\"\\/Date(1430199394957)\\/\"}]"}

$.each(data.d , function (i, field) { gives me :

$ .each（data.d，function（i，field）{给我：

TypeError: invalid 'in' operand a

2 个解决方案

#1

Bizarrely, the response from your server is a JSON object with a single property, d, which is a string containing the JSON for an array. If it's your server method generating that response, you probably want to adjust it so that data.d is an array, not a string.

奇怪的是，服务器的响应是一个带有单个属性d的JSON对象，它是一个包含数组JSON的字符串。如果是生成该响应的服务器方法，则可能需要调整它以使data.d是一个数组，而不是字符串。

To get those results and loop through them, you'll need to parse it, and then use field directly rather than via i:

要获得这些结果并循环遍历它们，您需要解析它，然后直接使用字段而不是通过i：

var fields = JSON.parse(data.d);
$.each(fields, function(i, field) {
    alert(field.BidderName);
});

or of course:

当然还是：

$.each(JSON.parse(data.d), function(i, field) {
    alert(field.BidderName);
});

Side note: As the parsed version of data.d is an array, on any modern browser you can use Array#forEach rather than $.each, which has a slightly less-confusing argument list for the callback. (Array#forEach can be easily polyfilled on IE8 and earlier.)

旁注：由于data.d的解析版本是一个数组，因此在任何现代浏览器中，您都可以使用Array＃forEach而不是$ .each，它有一个稍微不那么令人困惑的回调参数列表。（Array＃forEach可以在IE8及更早版本中轻松填充。）

JSON.parse(data.d).forEach(function(field) {
    alert(field.BidderName);
});

Live Example of both:

两个实例：

var data = {
    "d": "[{\"SrNo\":4,\"BidderName\":\"faisal\",\"BidAmt\":6000000.0000,\"BidDate\":\"\\/Date(1430199508063)\\/\"},{\"SrNo\":3,\"BidderName\":\"arbaaz jalil\",\"BidAmt\":5000010.0000,\"BidDate\":\"\\/Date(1430199494083)\\/\"},{\"SrNo\":2,\"BidderName\":\"arbaaz\",\"BidAmt\":500000.0000,\"BidDate\":\"\\/Date(1430199483530)\\/\"},{\"SrNo\":1,\"BidderName\":\"shekhar1\",\"BidAmt\":5000.0000,\"BidDate\":\"\\/Date(1430199394957)\\/\"}]"
};

snippet.log("Using $.each:");
$.each(JSON.parse(data.d), function(i, field) {
  snippet.log(field.BidderName);
});

snippet.log("----");
snippet.log("Using forEach");
JSON.parse(data.d).forEach(function(field) {
  snippet.log(field.BidderName);
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<!-- Script provides the `snippet` object, see http://meta.stackexchange.com/a/242144/134069 -->
<script src="http://tjcrowder.github.io/simple-snippets-console/snippet.js"></script>

#2

-1

The problem is that in var fiel you already have a each element of the array. The solutiobn is:

问题是在var fiel中你已经拥有了数组的每个元素。解决方案是：

$.each( obj, function (i, field) {
  alert(field.BidderName );
});

#1