Edit in JSFiddle

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

myApp.config(function(service){
    service.val = "config!!";
});

myApp.constant("service", {
    val: "defult value"
});

myApp.controller("myCtrl", function ($scope, service) {
    $scope.service = service;
});

<div ng-app="myApp">
    <div ng-controller="myCtrl">
        <p>val = {{service.val}}</p>
    </div>
</div>