在AngularJS中，有没有办法知道data.location中有重复，并且每个唯一的data.location只输出一次

Question

在AngularJS中，有没有办法知道data.location中有重复项，并且每个唯一的data.location只输出一次。 IE。而不是以下内容：

   A    Jane 
   A    Tom 
   B    Brian 
   B    Jane 
   B    Mike 
   R    Donald 
   R    Jerry

希望预期输出为：

   A    Jane 
        Tom  
   B    Brian 
        Jane 
        Mike 
   R    Donald  
        Jerry

angular代码如下：

<body ng-app="app" ng-controller="ctrl"> 
<table>
    <tr ng-repeat="data in output " >
      <td ng-bind="data.location"> </td>
      <td ng-bind="data.name"></td>
    </tr>
</table>   
<script>  
 angular.module('app', [])
  .controller('ctrl', function($scope) {
      $scope.output = [
        {name: "Jane ", location: "A"}, 
        {name: "Tom", location: "A"}, 
        {name: "Brian", location: "B"}, 
        {name: "Jane", location: "B"}, 
        {name: "Mike", location: "B"}, 
        {name: "Donald", location: "R"}, 
        {name: "Jerry", location: "R"}
      ] ; 
 });

Answer 1

angular.module('app', [])
   .controller('ctrl', function($scope) {
     $scope.output = [{
       name: "Jane ",
       location: "A"
     }, {
       name: "Tom",
       location: "A"
     }, {
       name: "Brian",
       location: "B"
     }, {
       name: "Jane",
       location: "B"
     }, {
       name: "Mike",
       location: "B"
     }, {
       name: "Donald",
       location: "R"
     }, {
       name: "Jerry",
       location: "R"
     }];
     
     var reduced = {};
   
     $scope.output.map(function(item){
         reduced[item.location] = reduced[item.location] || [];
         reduced[item.location].push(item.name);
     });
   
     $scope.reducedOutput = reduced;
   });

table, td{
  border: 1px solid black;
}

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

<body ng-app="app" ng-controller="ctrl">
  <table>
    <tr ng-repeat="(key, value) in reducedOutput">
      <td ng-bind="key"></td>
      <td>
        <ul>
          <li ng-repeat="val in value" ng-bind="val"></li>
        </ul>
      </td>
    </tr>
  </table>
</body>

在AngularJS中，有没有办法知道data.location中有重复，并且每个唯一的data.location只输出一次

In AngularJS, is there a way to know that there is duplicate in the data.location, and only output once for each unique data.location

filter

duplicates

angularjs

ng-repeat

angularjs-scope