Question

我有以下json：

{
  "code" : 400,
  "errors" : [ {
    "domain" : "global",
    "message" : "Invalid value for field 'instances[0]': 'scaler-group-instance-1'. The URL is malformed.",
    "reason" : "invalid"
  } ],
  "message" : "Invalid value for field 'instances[0]': 'scaler-group-instance-1'. The URL is malformed."
}

我希望能够为每个“体育”生成div并为每个“教练”生成子列表。

我该怎么做？当我尝试：

String projectId = "project-name-1";
String zoneName = "us-west1-a";
String instanceGroupName = "scaling-group-manager";
List<String> instancesToDelete = new ArrayList<>();
instancesToDelete.add("scaler-group-instance-1");
InstanceGroupManagersDeleteInstancesRequest deleteInstancesRequest = new InstanceGroupManagersDeleteInstancesRequest().setInstances(instancesToDelete);
Compute.InstanceGroupManagers.DeleteInstances deleteInstances = compute.instanceGroupManagers().deleteInstances(projectId, zoneName, instanceGroupName, deleteInstancesRequest).execute();

我收到的错误是分类[0]未定义...当我把它留作myobj.classifications并迭代它时，不会返回任何错误。我如何正确访问它？

Answer 1

只需添加一个安全的导航/ elvis操作符来检查数据是否存在，

将其更改为

<div  *ngFor="let sport of myobj?.classifications[0]?.sports;let i = index;">
{{sport}}
</div>

如何使用Angular2循环嵌套对象？

1 个答案: