访问对象时json解析不起作用

Question

  

可能重复：
  Fetching data from JSON.parse array

我是json的新手，不知道问题标题是否正确

我在obj中跟踪了这个语句'obj = ko.toJSON（viewModel）'中的json; viewmodel是一个淘汰视图。

{
"activeColumns": [
    {
        "property": "delete",
        "display": "Delete",
        "checked": true,
        "readonly": true
    },
    {
        "property": "id",
        "display": "ID",
        "checked": false,
        "readonly": true
    },
    {
        "property": "name",
        "display": "Name",
        "checked": false,
        "readonly": false
    },
    {
        "property": "age",
        "display": "Age",
        "checked": false,
        "readonly": false
    }
],
"rows": [
    {
        "selectedFruits": [],
        "id": 1,
        "name": "Bob",
        "age": 44
    },
    {
        "selectedFruits": [],
        "id": 2,
        "name": "Ted",
        "age": 22
    },
    {
        "selectedFruits": [],
        "id": 3,
        "name": "Jane",
        "age": 55
    },
    {
        "selectedFruits": [],
        "id": 4,
        "name": "Sue",
        "age": 11
    }
],
"newName": "",
"lastSavedJson": "",
"newAge": "",
"newAttribute": "",
"males": 10,
"females": 90,
"val": 50,
"selectedValue": "select",
"selectedCategory": "select",
"availablecategory": [
    "select",
    "functional",
    "non-functional",
    "technical"
],
"tshirtoptions": [
    "select",
    "S",
    "M",
    "L",
    "XL",
    "XXL"
],
"availableparametertype": [
    "select",
    "range",
    "numeric",
    "percentage",
    "t-shirt"
]
}

我正在使用obj.activeColumns（）[0]访问第一个数组，但它显示未捕获的类型错误。如何访问不同的对象数组及其属性，然后再如何删除特定对象。感谢...