AngularJS on click

HTML

<div ng-app ng-controller="MyCtrl">
    <div> {{ name}}</div>
   
    <input type="submit" ng-click="btn123()" value="button"></input>
   
</div>

JavaScript

function MyCtrl($scope) {
    $scope.name = "Hello";

    $scope.btn = function () {
        $scope.name = "Changed";
    };
}