Angular input directive 1.2.0

HTML

<script src="http://code.angularjs.org/1.2.0/angular.min.js"></script>
<div ng-controller="MyCtrl">{{ timesChanged }}</div>

JavaScript

var app = angular.module('myApp', []);

function MyCtrl($scope) {

    $scope.string = 'Hello.';
    $scope.timesChanged = 0;

    $scope.$watch('string', function (newValue) {
        $scope.timesChanged =+ 1;
    });
    
    $scope.string = 'How are you';
    $scope.string = 'doing today?';

}