Hello World Angular JS - Service

HTML

<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.0.6/angular.min.js"></script>
<script src="http://searls.github.io/jasmine-all/jasmine-all-min.js"></script>
<script src="http://code.angularjs.org/1.0.6/angular-mocks.js"></script>
<div ng-app="helloWorldApp">
    <div ng-controller="HelloWorldCtrl">
        <button ng-click="embaralhar()">Embaralhar</button>
        <p>Lista</p>
        <ul>
            <li ng-repeat="item in array">{{item.id}}: {{item.nome}}</li>
        </ul>
        Total de Cidades: {{array.length}}
    </div>
</div>

CSS

.ng-invalid {
    border: 1px solid red;
}

ul {list-style-type: square;}

JavaScript

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

helloWorldApp.controller('HelloWorldCtrl', function ($scope, randomSortService, $window) {
    $scope.nome = "mundo";
    $scope.numero = 123;

    $scope.digaOla = function () {
        $window.alert("Olá " + $scope.nome + "!");
    }

    $scope.array = [{
        id: 1,
        nome: "SALVADOR"
    },{
        id: 2,
        nome: "RIO DE JANEIRO"
    },{
        id: 3,
        nome: "FLORIANOPOLIS"
    },{
        id: 4,
        nome: "SÃO PAULO"
    },{
        id: 5,
        nome: "RECIFE"
    },{
        id: 6,
        nome: "NATAL"
    }];

    $scope.embaralhar = function () {
        randomSortService.sort($scope.array);
    };
});

helloWorldApp.service('randomSortService', function ($rootScope) {
    this.sort = function (array) {
        for (var i = array.length - 1; i > 0; i--) {
            var j = Math.floor(Math.random() * (i + 1));
            var temp = array[i];
            array[i] = array[j];
            array[j] = temp;
        }
        return array;
    };
});