How to install packages using npm install

The node package manager (npm) installs the packages required in a JavaScript project ​and provides a useful interface on which these packages can work.

Syntax

The following command is used to install packages using npm.

npm install <@scope>/<name>

Here, the scope specifies whether the package is to be installed locally or globally. The name is simply the name of the package to be installed.

If there is no package.json file in the local directory, then the latest version of the package is installed. If there is a package.json file, npm will install the latest version that satisfies the semver rule declared in package.json.

Code

The following codes demonstrates various variations on the npm install command.

1. Installing packages locally

The following command installs any third-party module in the project’s folder.

npm install <package name>

This creates a node_modules directory in the project’s current directory (if one doesn’t exist yet) and downloads the package to that directory.

For example, to install the ExpressJS package, simply write the command:

npm install express

2. Installing packages globally

The following command installs global packages into the /User/local/lib/node_modules folder.

npm install -g <package name>

The command to install the ExpressJS package globally would then be:

npm install -g express

3. Installing a package with dist-tags

npm install <package_name> will use the latest tag by default.

To override this behavior, use the command below (where tag is the package’s tag like beta, latest, etc.).

 npm install <package_name>@<tag>. 

To install a specific version of the ExpressJS library, type:

 npm install express@beta.