Angularjs：当使用ng-value时，value = 0？

Question

我有一个奇怪的错误。当我使用ng-value时，页面会为某些选项呈现'value = 0'。控制台不显示错误。

以下是代码：

<option ng-repeat="x in makes" ng-value="{{x.make_id}}">{{x.make}}</option>

结果如下：

<option ng-repeat="x in makes" ng-value="acura" class="ng-binding ng-scope">ACURA</option>
<!-- end ngRepeat: x in makes -->
<option ng-repeat="x in makes" ng-value="alfa-romeo" class="ng-binding ng-scope" value="0">ALFA ROMEO</option>
<!-- end ngRepeat: x in makes -->
<option ng-repeat="x in makes" ng-value="alpina" class="ng-binding ng-scope">ALPINA</option>
<!-- end ngRepeat: x in makes -->
<option ng-repeat="x in makes" ng-value="armstrong-siddeley" class="ng-binding ng-scope" value="0">ARMSTRONG SIDDELEY</option>

Answer 1

不要绑定表达式。 ngValue使用$eval数据绑定，这意味着您应该删除{{ }}

<option ng-repeat="x in makes" ng-value="x.make_id">{{x.make}}</option>

编辑：AngularJS文档中没有很好地记录这一点。