In order to use almost any development tools based in JavaScript, you'll need to know how to use npm and Node.js. Gulp, Grunt, and Webpack are a few examples of popular technologies you may have heard of that require a knowledge of the Node ecosystem.
I find myself writing about this over and over again in the prerequisites of an article I've begun to write. I'd prefer to write one definitive guide to refer to in the future, so here it is.
NPM is a “package manager” that makes installing Node “packages” fast and easy. A package, also called a module, is just a code library that extends Node by adding useful features. For example, the “request” module simplifies the process of making HTTP requests so you can easily get web resources from other sites. Npm makes it easy for JavaScript developers to share and reuse code, and makes it easy to update the code that you’re sharing, so you can build amazing things. Before starting the installation of Node.js and NPM using this tutorial you must have the following prerequisites. Terminal: You must have Mac Terminal access and little knowledge about working with the terminal application. Ao login to your Mac system and open terminal; Homebrew: Homebrew is a popular package manager for the Mac operating.
Prerequisites
- Basic command line proficiency. Don't skip this step! If you don't know how to use the command line, you'll be fighting an uphill battle. The provided tutorial has everything you need to know.
Goals
- Learn what Node.js and npm are
- Set up Node.js and npm on Windows and Mac
What is Node.js?
JavaScript is a client-side programming language, which means it’s processed in the browser. With the advent of Node.js, JavaScript can also be used as a server-side language.
What is npm?
npm doesn't stand for Node Package Manager*, which means it’s the tool to connect to the repository containing all the Node.js programs, plugins, modules and so on.
*npm actually does not stand for 'Node Package Manager' but essentially that's what it is and does, so most people refer to it that way.
Local vs. Global
This is the most confusing concept to understand at first, so it's important to let this settle in. Traditionally, you're used to globally installing any sort of program or software on your computer. If you want Spotify, you'll download Spotify, and then it will be available to you.
With npm, you will have some global installs, but mostly everything will be done on a local project basis, meaning you'll have to install everything you need for each project in its own directory. If you want to have a project running Gulp and Sass, you'll create a directory, with a new npm install.
For future reference, any global installations will have the -g flag.
Installation on Windows
Installing everything on Windows is a breeze.
Install Node.js and npm
Node.js and npm can be installed from a download link. Go to the Node installation page, and download the Node installer. I have a 64-bit Windows 10 OS, so I chose that one.
Once it's done, you can test to see both node and npm functioning by opening PowerShell (or any shell) and typing node -v and npm -v, which will check the version number.
All set.
Installation on a Mac or Linux
In order to install everything on a Mac, we'll be running commands in Terminal.app, and Linux distributions vary.
Install Node.js and npm
We’re going to use Node Version Manager (nvm) to install Node.js and npm.
Open the ~/.bash_profile file, and make sure source ~/.bashrc is written in there somewhere. Restart the terminal.
Run the install command.
Run the use command.
Now that Node.js and npm are installed, test them by typing node -v and npm -v.
All set.
Create a Project
At this point, you're set to start setting up Gulp, Webpack, Browserify, or whatever your aim is. We can also create a simple project to test that everything is working properly.
Madden NFL 2002 includes all the hard-hitting action and authentic player details you expect.plus a few new surprises. New features include Madden Cards and all 31 NFL coaches realistically rendered using EA Sports® Cyberscan technology. Madden NFL 2002. Madden NFL 2002. Summary: Play a full season with your favorite team and take them to the Super Bowl, or try the franchise mode and build a dynasty. Franchises:Madden NFL. Madden NFL 2002 (also known as Madden 2002) is an American football video game. It features former Minnesota Vikings quarterback Daunte Culpepper on the cover. Pat Summerall and John Madden are the commentators. 
Madden NFL 2002 was the first football simulation game to feature the expansion team, the Houston Texans in the team select. This game allows you to create your own teams and players from scratch. Madden NFL 2002 features more realistic player animations, Madden Cards, a training mode, and a lot of other features.
Initialize Project
Navigate to the directory in which you want your project to exist - in my case, sites/node-test.
Now initalize a new project with npm.
The following will pop up in the terminal, and prompt you for a few
First, it will ask for a package name. Disk utility tool for windows to format usb in mac.
Version number.
Description.
The rest you can just press enter and skip. Now you'll notice we have a package.json file that contains all the information we entered.
A package.json is a file that contains metadata about the project, and handles the dependencies (additional software and modules) of the project.
Now, we're going to install our first dependency - a very important and useful package called left-pad, which will add white space to the left side of a string, adding up to a number.
For example, writing this:
Will output this:
left-pad is a package on npm, which as we stated previously contains the registry for all publicly available packages.
Install dependencies
To install a dependency with npm, we use the command npm install dependency-name-here. Now, simply running npm install will download the dependency, but it won't save it to the project. Since we've already created our package.json, we'll use the flag --save to install the dependency and add it to package.json.
Npm Mac Permission Denied
As long as you ran this command inside the project directory, it will successfully install the dependency by creating a node_modules directory. It will also create a package-lock.json file, which we can ignore. Finally, it updated our package.json file with a new line.
Now the project recognizes the left-pad dependency as existing
You can also run npm install --save-dev to specify that the dependency will only be used for development (not production) purposes.
Run Node in the terminal
Npm Install For Mac
Let's create index.js in the root of our directory. This is everything you should have now:
For future reference, don't bother looking in the node_modules rabbit hole. It will get really overwhelming with bigger projects.
In order to use a dependency, we use require() and put it in a variable, like so:
This will be the entirety of our index.js file, in which we require left-pad, run a leftPad() function, and send it to the console.
Since Node.js is not recognized by the browser, we'll be testing this in the console. In your shell, run the node command followed by the filename in the root of your project.
If everything went well, you should have printed Hello, World! to the console, with two spaces on the left.
Conclusion
In this tutorial, we learned the following:
- What Node.js is
- What npm is
- How to install Node.js and npm on Windows or Mac
- How to make a local project
- How to install a dependency with npm
- How to run a file using a node_modules dependency in a shell
Npm Install For Mac
If you got lost at any point, view the source on GitHub.
With this knowledge, you're ready to start using Gulp, Grunt, Webpack, Browserify, or anything else that depends on Node.js or npm.
node.js allows you to run javascript in the Terminal as appose to a regular browser which makes for a modern workflow in web development, with node.js installed an associated package called npm (Node Package Manager) is also installed which can manage other applications that utilize node.js, one of the main ones being grunt.js. OSX Yosemite 10.10 guide here.
To install node.js on OSX 10.9 Mavericks you can download a pre-compiled binary package which makes a nice and easy installation. Head over to http://nodejs.org/ and click the install button to download the latest package.
Install the package by following along which will install node and npm, npm is Node Package Manager which facilitates installs of additional packages for node.js.
At the end of the install you are prompted to make sure that /usr/local/bin is in your path, double check you have it by running in the Terminal:
Npm For Mac Os X
After install check it was ok by entering in the command line node which will open a node javascript session:
To exit the node.js session just hit ‘control’ + ‘c’ twice.
If you have an earlier version of node you can just download the latest version and install to upgrade it and it will overight the previous version.
Installing Packages for Node
There are many packages for Node such as the popular grunt.js, you use the command npm to see a complete list run:
Npm For Mac M1
This will return an exhaustive list of available packages, to install a package run npm install
To list installed packages run
Download Npm For Mac
To upgrade npm packages
Npm For Mac
To upgrade node.js itself on OSX just download and install the latest from node.org