Question

我有以下JSON：

{
   "responseObject": {
   "name": "ObjectName",
   "fields": [
   {
     "fieldName": "refId",
     "value": "2170gga35511"
   },
   {
     "fieldName": "telNum",
     "value": "4541885881"
   }]}
}

我想使用"value"访问数组元素的"fieldName": "telNum"而不使用索引号，因为我不知道每次都会确切地显示此telNum元素的位置。< / p>

我梦想的是这样的事情：

jsonVarName .responseObject.fields [ '字段名'= 'telNum']。值

这在JavaScript中是否可行？

Answer 1

你可以这样做

var k={
   "responseObject": {
   "name": "ObjectName",
   "fields": [
   {
     "fieldName": "refId",
     "value": "2170gga35511"
   },
   {
     "fieldName": "telNum",
     "value": "4541885881"
   }]
}};
value1=k.responseObject.fields.find(
function(i)
{return (i.fieldName=="telNum")}).value;
console.log(value1);

Answer 2

这是不可能的..原生JavaScript没有类似XPATH的类似于xml来迭代JSON。您必须按照评论中的说明循环或使用Array.prototype.find()。它是实验性的，仅支持Chrome 45 +，Safari 7.1 +，FF 25+。没有IE。

可以找到示例here

Answer 3

有JSONPath可以让你像XPATH一样编写查询。

$.store.book[*].author  the authors of all books in the store
$..author               all authors
$.store.*               all things in store, which are some books and a red bicycle.
$.store..price          the price of everything in the store.
$..book[2]              the third book
$..book[(@.length-1)] 
$..book[-1:]            the last book in order.
$..book[0,1]
$..book[:2]             the first two books
$..book[?(@.isbn)]      filter all books with isbn number
$..book[?(@.price<10)]  filter all books cheapier than 10
$..*                    All members of JSON structure.

Answer 4

使用fieldName作为键将数组修改为对象可能是一个更好的选择，以避免一遍又一遍地使用.find。

fields = Object.assign({}, ...fields.map(field => {
    const newField = {};
    newField[field.fieldName] = field.value;
    return newField;
}

Answer 5

你必须循环找到它。

＆＃13;

SwingWorker

＆＃13;

Answer 6

只需循环遍历数组的简洁方法。

var json = {
   "responseObject": {
   "name": "ObjectName",
   "fields": [
    {
     "fieldName": "refId",
     "value": "2170gga35511"
    },
  {
    "fieldName": "telNum",
    "value": "4541885881"
  }]
 }   
  $(json.responseObject.fields).each(function (i, field) {
    if (field.fieldName === "telNum") {

      return field.value // break each
    }
  })

是否可以在不使用索引号的情况下访问json数组元素？

6 个答案: