我删除了package.json和Gruntfile.js，现在Grunt将不会加载依赖项

Question

So by accident I deleted my package.json and Gruntfile folder from my project directory and before I did that I already ran grunt and grunt jshint and it ran perfectly fine. I re-made both files (package.json and Gruntfile.js) and now when I try to run grunt or grunt jshint It tells me..

PS C:\Users\Vincent\desktop\projects\kittenbook> grunt jshint
>> Local Npm module "grunt-contrib-concat" not found. Is it installed?
>> Local Npm module "grunt-contrib-copy" not found. Is it installed?
>> Local Npm module "grunt-contrib-jshint" not found. Is it installed?
Warning: Task "jshint" not found. Use --force to continue.

Then Powershell crashes soon after.

Npm works I already checked and I know Grunt is obviously installed.

Here's my Gruntfile.js which I had to re-make. It ran perfectly fine before I deleted my package.json file..

module.exports = function(grunt) {
    grunt.initConfig({
        concat: {
        release: {
            src: ['js/values.js', 'js/prompt.js'],
            dest: 'release/main.js'
        }
      },
      copy: {
          release: {
              src: 'manifest.json',
              dest: 'release/manifest.json'
          }
      },
      jshint: {
          files: ['js/values.js', 'js/prompt.js']
      }
    });

    // Load Grunt plugin
    grunt.loadNpmTasks('grunt-contrib-concat');
    grunt.loadNpmTasks('grunt-contrib-copy');
    grunt.loadNpmTasks('grunt-contrib-jshint');

    // Register tasks
    grunt.registerTask('default', ['jshint', 'concat', 'copy']);

};

Here's the new package.json file

{
  "name": "kittenbook",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "devDependencies": {
    "grunt": "^0.4.5",
    "grunt-contrib-concat": "^0.3.0",
    "grunt-contrib-copy": "^0.5.0",
    "grunt-contrib-jshint": "^0.6.5",
    "grunt-contrib-watch": "^1.0.0"
  }

}

Also Should I run the Gruntfile above even though I already ran it the first time? Will that mess anything up?

I hope this is not too confusing. I'm new at programming. Thanks!

Update: When I try to run npm install

PS C:\Users\Vincent> cd desktop/projects/kittenbook
PS C:\Users\Vincent\desktop\projects\kittenbook> npm install
npm WARN package.json kittenbook@1.0.0 No description
npm WARN package.json kittenbook@1.0.0 No repository field.
npm WARN package.json kittenbook@1.0.0 No README data
npm WARN package.json kittenbook@1.0.0 No license field.

UPDATE: The mistake I made was that the Gruntfile.js was outside of my projects folder.. Wow.. lol. Problem solved.

Answer 1

In command prompt go to the directory of your project and run the following command.

npm install

You may have to open command prompt with administrator privileges for this to work.

This will install all the npm modules defined in the package.json file.