如何在AngularJS中更新同一key上的Json数据？

app.controller('MyController', function($scope) {
  $scope.myData = {
    key1: 'value1',
    key2: 'value2',
    key3: 'value3'
  };
});

<input type="text" ng-model="myData.key1">

app.controller('MyController', function($scope) {
  $scope.myData = {
    key1: 'value1',
    key2: 'value2',
    key3: 'value3'
  };

  $scope.updateData = function() {
    $scope.myData.key1 = 'new value';
  };
});

<button ng-click="updateData()">Update Data</button>