I'm new to the Grunt world.

After installing grunt-cli, and all the dependencies, here is my : Gruntfile.js

/*

        Grunt installation:

        -------------------

            npm install -g grunt-cli

            npm install -g grunt-init

            npm init (creates a `package.json` file)



        Project Dependencies:

        ---------------------

            npm install grunt --save-dev

            npm install grunt-contrib-concat --save-dev

            npm install grunt-contrib-watch --save-dev







        Example Usage:

        --------------

            grunt -v

            grunt release -v



*/





module.exports = function(grunt) {

    "use strict";



    grunt.initConfig({



        concat: {



            js: {

                src: ['js/bootstrap.min.js', 'js/jquery-1.10.2.min.js'],

                dest: 'build/js/scripts.js'

            },



            css: {

                src: ['css/bootstrap.min.css', 'css/font-awesome.min.css'],

                dest: 'build/css/styles.css'

            }

        },



        watch: {



            js: {

                files: ['js/**/*.js'],

                task: ['concat:js']

            },



            css: {

                files: ['css/**/*.css'],

                task: ['concat:css']

            }

        }



    });



    grunt.loadNpmTasks('grunt-contrib-concat');

    grunt.loadNpmTasksNpmTasks('grunt-contrib-watch');

    grunt.registerTask('default', ['concat', 'watch']);



};

Result

Now the testing part, I tried run grunt, I kept getting :

Loading "Gruntfile.js" tasks...ERROR

>> TypeError: undefined is not a function

Warning: Task "default" not found. Use --force to continue.



Aborted due to warnings.

Can someone please tell me what did I do wrong here ?