为什么我无法获得数组长度

Question

我需要有关数组长度的帮助。

我尝试使用Object.keys

{  
   "@odata.context":"https://graph.microsoft.com/v1.0/$metadata#sites('volagas.sharepoint.com')/sites('volagas.sharepoint.com%2C9a51e995-62f9-4b40-81c2-d167c4c79182%2C2646bdf6-214f-482c-826f-c5e21676a79c')/lists('84885DBF-980E-4AD2-8377-AAB746E6D41A')/items",
   "value":[  
      {  
         "@odata.etag":"\"dfd2e718-5cac-4d7a-b8b3-7dba435dae29,3\"",
         "createdDateTime":"2018-11-26T11:03:29Z",
         "eTag":"\"dfd2e718-5cac-4d7a-b8b3-7dba435dae29,3\"",
         "id":"1",
         "lastModifiedDateTime":"2018-11-27T10:40:11Z",
         "webUrl":"https://volagas.sharepoint.com/doc/Lists/List60/1_.000",
         "createdBy":{  
            "user":{  
               "email":"d.kalinin@volgagas.com",
               "id":"1606566d-042b-4761-8229-ddd3a4e4a8b9",
               "displayName":"Данил Калинин"
            }
         },
         "lastModifiedBy":{  
            "user":{  
               "email":"d.kalinin@volgagas.com",
               "id":"1606566d-042b-4761-8229-ddd3a4e4a8b9",
               "displayName":"Данил Калинин"
            }
         },
         "parentReference":{  

         },
         "contentType":{  
            "id":"0x01004865A45A1D8A8C4FA163CEB418DD12E6"
         },
         "fields@odata.context":"https://graph.microsoft.com/v1.0/$metadata#sites('volagas.sharepoint.com')/sites('volagas.sharepoint.com%2C9a51e995-62f9-4b40-81c2-d167c4c79182%2C2646bdf6-214f-482c-826f-c5e21676a79c')/lists('84885DBF-980E-4AD2-8377-AAB746E6D41A')/items('1')/fields/$entity",
         "fields":{  
            "@odata.etag":"\"dfd2e718-5cac-4d7a-b8b3-7dba435dae29,3\"",
            "Title":"тест_1_edited",
            "LinkTitleNoMenu":"тест_1_edited",
            "LinkTitle":"тест_1_edited",
            "ShipmentDateTime":"2018-11-29T21:00:00Z",
            "Good":"Нефть",
            "PricePerTon@odata.type":"#Single",
            "PricePerTon":5000,
            "Contractor":"TESTCONTRACTOR_1",
            "CarNumber":"TESTCONTRACTOR_1",
            "TankNumber":"TESTCONTRACTOR_1",
            "DriverName":"TESTCONTRACTOR_1",
            "Status":"Свободно",
            "_x0421__x0447__x0435__x0442_":"Выслать счет",
            "Payment":false,
            "id":"1",
            "ContentType":"Элемент",
            "Modified":"2018-11-27T10:40:11Z",
            "Created":"2018-11-26T11:03:29Z",
            "AuthorLookupId":"2211",
            "EditorLookupId":"2211",
            "_UIVersionString":"1.0",
            "Attachments":false,
            "Edit":"",
            "ItemChildCount":"0",
            "FolderChildCount":"0",
            "_ComplianceFlags":"",
            "_ComplianceTag":"",
            "_ComplianceTagWrittenTime":"",
            "_ComplianceTagUserId":""
         }
      },
      {  
         "@odata.etag":"\"4c72729b-d43a-47c5-acab-0a5e9a9f64f8,3\"",
         "createdDateTime":"2018-11-27T06:18:51Z",
         "eTag":"\"4c72729b-d43a-47c5-acab-0a5e9a9f64f8,3\"",
         "id":"2",
         "lastModifiedDateTime":"2018-11-27T10:40:20Z",
         "webUrl":"https://volagas.sharepoint.com/doc/Lists/List60/2_.000",
         "createdBy":{  
            "user":{  
               "email":"d.kalinin@volgagas.com",
               "id":"1606566d-042b-4761-8229-ddd3a4e4a8b9",
               "displayName":"Данил Калинин"
            }
         },
         "lastModifiedBy":{  
            "user":{  
               "email":"d.kalinin@volgagas.com",
               "id":"1606566d-042b-4761-8229-ddd3a4e4a8b9",
               "displayName":"Данил Калинин"
            }
         },
         "parentReference":{  

         },
         "contentType":{  
            "id":"0x01004865A45A1D8A8C4FA163CEB418DD12E6"
         },
         "fields@odata.context":"https://graph.microsoft.com/v1.0/$metadata#sites('volagas.sharepoint.com')/sites('volagas.sharepoint.com%2C9a51e995-62f9-4b40-81c2-d167c4c79182%2C2646bdf6-214f-482c-826f-c5e21676a79c')/lists('84885DBF-980E-4AD2-8377-AAB746E6D41A')/items('2')/fields/$entity",
         "fields":{  
            "@odata.etag":"\"4c72729b-d43a-47c5-acab-0a5e9a9f64f8,3\"",
            "Title":"тест_2",
            "LinkTitleNoMenu":"тест_2",
            "LinkTitle":"тест_2",
            "ShipmentDateTime":"2018-12-01T21:00:00Z",
            "Good":"ГК",
            "PricePerTon@odata.type":"#Single",
            "PricePerTon":10000,
            "Contractor":"CONTRACTOR2",
            "CarNumber":"У152КХ",
            "TankNumber":"Б554ЕН",
            "DriverName":"Иванов Иван Иванович",
            "Status":"Свободно",
            "_x0421__x0447__x0435__x0442_":"Выслать счет",
            "Payment":true,
            "id":"2",
            "ContentType":"Элемент",
            "Modified":"2018-11-27T10:40:20Z",
            "Created":"2018-11-27T06:18:51Z",
            "AuthorLookupId":"2211",
            "EditorLookupId":"2211",
            "_UIVersionString":"1.0",
            "Attachments":false,
            "Edit":"",
            "ItemChildCount":"0",
            "FolderChildCount":"0",
            "_ComplianceFlags":"",
            "_ComplianceTag":"",
            "_ComplianceTagWrittenTime":"",
            "_ComplianceTagUserId":""
         }
      }
   ]
}

为什么我不能得到value.lenght？

有一个假设是由于引号引起的。在那种情况下，所有问题都是一样的-如何纠正？

它不解析

我尝试使用Object.keys

您对此有何想法？

Answer 1

您的媒体资源是Object，而不是array。

获取length根的object。

var length_object = Object.keys(your_object).length;

获取您的“值”的length

var length_values = your_object['value'].length;

Answer 2

将此对象分配给variable解决了该问题。将其设置为：

var obj = { /* your object here */ }
console.log(obj.value.length) // returns 2

由于它在问题中的呈现方式没有将该对象分配给任何对象，因此无法访问value及其length的属性