JSON数组.length属性不起作用答案

【问题标题】：JSON array .length property not workingJSON数组.length属性不起作用
【发布时间】：2015-09-02 16:43:45
【问题描述】：

我有以下 JSON 数组：

[  
   {  
      "orderStatus":"S",
      "x_ExtnIsModifiable":"N",
      "grandTotal":"24",
      "orderId":"",
      "grandTotalCurrency":"USD",
      "placedDate":"2015-05-11T17:56:27.406Z",
      "x_ExtnIsModifiableUntil":"2012-07-24 23:59:00.0",
      "externalOrderID":"29001e"
   },
   {  
      "orderStatus":"S",
      "x_ExtnIsModifiable":"N",
      "grandTotal":"23",
      "orderId":"",
      "grandTotalCurrency":"USD",
      "placedDate":"2015-04-11T17:56:27.406Z",
      "x_ExtnIsModifiableUntil":"2012-07-24 23:59:00.0",
      "externalOrderID":"29001d"
   },
   {  
      "orderStatus":"S",
      "x_ExtnIsModifiable":"N",
      "grandTotal":"22",
      "orderId":"",
      "grandTotalCurrency":"USD",
      "placedDate":"2015-03-11T17:56:27.406Z",
      "x_ExtnIsModifiableUntil":"2012-07-24 23:59:00.0",
      "externalOrderID":"29001c"
   }
]

这个数组被命名为“OrderStatusArray”。我试图在不对其进行硬编码的情况下获取数组的长度（出于显而易见的原因），但我不知道该怎么做。我在 SO 上看到过十几篇帖子说我应该能够通过 OrderStatusArray.length 来获取数组的长度，但这对我不起作用。

如何获得这个数组的长度？

【问题讨论】：

你的代码在哪里？ “但这对我不起作用”是什么意思？有没有发现任何错误？
正如大家所说，用.length：jsfiddle.net/203w81Lk
为我工作。也许您正在使用一些古老的浏览器？
${ allOrdersInThisCategory } 是一种什么样的 JavaScript 语法？你在哪里使用它？
但是 Websphere 商务是 Java，不是吗？在您向我们展示的这段代码中，没有使用.length。请参阅How to create a Minimal, Complete, and Verifiable example。

标签： javascript arrays json

【解决方案1】：

看到这个小提琴：https://jsfiddle.net/x983vvr6/2/

基本上，假设您已经正确设置了您只需要调用的对象

OrderStatusArray.length

它会显示数组的长度。

您期望的长度是多少？ 3是正确答案和这个小提琴显示的答案。

完整代码：

var OrderStatusArray = [{
"orderStatus": "S",
    "x_ExtnIsModifiable": "N",
    "grandTotal": "24",
    "orderId": "",
    "grandTotalCurrency": "USD",
    "placedDate": "2015-05-11T17:56:27.406Z",
    "x_ExtnIsModifiableUntil": "2012-07-24 23:59:00.0",
    "externalOrderID": "29001e"
  }, {
"orderStatus": "S",
    "x_ExtnIsModifiable": "N",
    "grandTotal": "23",
    "orderId": "",
    "grandTotalCurrency": "USD",
    "placedDate": "2015-04-11T17:56:27.406Z",
    "x_ExtnIsModifiableUntil": "2012-07-24 23:59:00.0",
    "externalOrderID": "29001d"
   }, {
"orderStatus": "S",
    "x_ExtnIsModifiable": "N",
    "grandTotal": "22",
    "orderId": "",
    "grandTotalCurrency": "USD",
    "placedDate": "2015-03-11T17:56:27.406Z",
    "x_ExtnIsModifiableUntil": "2012-07-24 23:59:00.0",
    "externalOrderID": "29001c"
     }];


console.log("Your order length array is: " + OrderStatusArray.length);

【讨论】：

【解决方案2】：

var data = [  
   {  
      "orderStatus":"S",
      "x_ExtnIsModifiable":"N",
      "grandTotal":"24",
      "orderId":"",
      "grandTotalCurrency":"USD",
      "placedDate":"2015-05-11T17:56:27.406Z",
      "x_ExtnIsModifiableUntil":"2012-07-24 23:59:00.0",
      "externalOrderID":"29001e"
   },
   {  
      "orderStatus":"S",
      "x_ExtnIsModifiable":"N",
      "grandTotal":"23",
      "orderId":"",
      "grandTotalCurrency":"USD",
      "placedDate":"2015-04-11T17:56:27.406Z",
      "x_ExtnIsModifiableUntil":"2012-07-24 23:59:00.0",
      "externalOrderID":"29001d"
   },
   {  
      "orderStatus":"S",
      "x_ExtnIsModifiable":"N",
      "grandTotal":"22",
      "orderId":"",
      "grandTotalCurrency":"USD",
      "placedDate":"2015-03-11T17:56:27.406Z",
      "x_ExtnIsModifiableUntil":"2012-07-24 23:59:00.0",
      "externalOrderID":"29001c"
   }
];
console.log( data.length );

你想要这个吗？

【讨论】：