我很难理解ng选项如何工作与数据源。我读过文档，我觉得我做的正是所需要的，但我仍然遇到问题时尝试。
<!DOCTYPE html>
<html ng-app="app">
<head>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.1.5/angular.min.js"> </script>
<link rel="stylesheet" href="style.css" />
<script type="text/javascript">
angular.module('app',[])
.controller('IndexCtrl',['$scope',function($scope) {
$scope.types = {
1: "value1",2: "value2",5: "value3"
};
}]);
</script>
</head>
<body ng-controller="IndexCtrl">
<select ng-model="type" ng-options="k as v for(k,v) in types">
<option value="">Select Type</option>
</select>
</body>
</html>
我总是在控制台中得到这个错误：
错误：
Expected ngOptions in form of ‘select (as label)? for (key,)?value in collection (track by expr)?’ but got ‘k as v for(k,v) in types’.
我做错了什么？
请参见plunkr：
http://plnkr.co/edit/Bl6u4151KyDkxhYrsdCm?p=preview
这是一种奇怪，但它似乎你需要放一个空间后。这工作：
<select ng-model="type" ng-options="k as v for (k,v) in types"> <option value="">Select Type</option> </select>