AngularJS - Sharing variables between controllers

This question already has an answer here:

AngularJS: How can I pass variables between controllers? 15 answers

I know this has been posted before but I am still confused on how to achieve this for my specific problem.

my first controller:

myApp.controller("buttonCtrl", function($scope){
    $scope.johnny = [
        {quote: "Anything for My Princess", controller: Princess},
        {quote: "Don't Even Ask", controller: DontAsk}];
}

Now I would like to use the $scope.johnny object in this controller:

function Princess($scope){

    $scope.play = function(){
    //use $scope.johnny.quote or something of the sorts in here
    }
}

How would this be done? I have seen posts where $rootScope or services are used; however, how would I implement one in my case.

Thanks a lot.

Use Angular JS Services/ Factories

A sample example is shown below

Working Demo

HTML

<div ng-app='myApp'>
    <div ng-controller="ControllerOne">
        <button ng-click="getUserOne()">User One</button>
    </div>
    <div ng-controller="ControllerTwo">
        <button ng-click="getUserTwo()">User Two</button>
    </div>
</div>

SCRIPT

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

app.factory('userFactory', function () {
    return {
        users: [{
            userId: 1,
            userName: "Jhonny"
        }, {
            userId: 2,
            userName: "Sunny"
        }]
    }
});

app.controller('ControllerOne', function ($scope, userFactory) {
    $scope.getUserOne = function () {
        alert(JSON.stringify(userFactory.users[0]));
    }

});

app.controller('ControllerTwo', function ($scope, userFactory) {
    $scope.getUserTwo = function () {
        alert(JSON.stringify(userFactory.users[1]));
    }

});

Also take a look at this stuff

How can I pass variables between controllers in AngularJS?