Setup Different Environment in AngularJS

'use strict';
/*
@author
Himanshu Goyal
*/
module.exports = function (grunt) {

    /*  */
    grunt.loadNpmTasks('grunt-ng-constant');

    grunt.initConfig({
        ngconstant: {
            development: {
                options: {
                    dest: './config/config.constant.js',
                    space: ' ',
                    wrap: '\n\n {%= __ngModule %}',
                    name: 'UrlConfiguration',
                },
                constants: {
                    $enviornment: require('./config/development.json')
                }
            },
            staging: {
                options: {
                    dest: './config/config.constant.js',
                    space: ' ',
                    wrap: '\n\n {%= __ngModule %}',
                    name: 'UrlConfiguration',
                },
                constants: {
                    $enviornment: require('./config/staging.json')
                }
            },
            production: {
                options: {
                    dest: './config/config.constant.js',
                    space: ' ',
                    wrap: '\n\n {%= __ngModule %}',
                    name: 'UrlConfiguration',
                },
                constants: {
                    $enviornment: require('./config/production.json')
                }
            }
        }
    });

    grunt.registerTask('buildenv', function (n) {
        console.log("you are building  " + n);
        grunt.task.run('ngconstant:' + n)
    })
};
//file generate after grunt command run

 angular.module('UrlConfiguration', [])
.constant('$enviornment', {name:'production',url:'http://localhost:8080/'});

//sample file of production url
{
    "name":"production",
    "url":"http://localhost:8080/"
}

THANKS