The difference between npm install and npm update handling of package versions specified in package.json:
{
"name": "my-project",
"version": "1.0", // install update
"dependencies": { // ------------------
"already-installed-versionless-module": "*", // ignores "1.0" -> "1.1"
"already-installed-semver-module": "^1.4.3" // ignores "1.4.3" -> "1.5.2"
"already-installed-versioned-module": "3.4.1" // ignores ignores
"not-yet-installed-versionless-module": "*", // installs installs
"not-yet-installed-semver-module": "^4.2.1" // installs installs
"not-yet-installed-versioned-module": "2.7.8" // installs installs
}
}
Summary: The only big difference is that an already installed module with fuzzy versioning ...
npm install
npm update
Additionally: install
and update
by default handle devDependencies differently
npm install
will install/update devDependencies unless --production
flag is addednpm update
will ignore devDependencies unless --dev
flag is addedWhy use npm install
at all?
Because npm install
does more when you look besides handling your dependencies in package.json
.
As you can see in npm install you can ...
PATH
) using npm install -g <name>
--force
Many distinctions have already been mentioned. Here is one more:
Running npm install
at the top of your source directory will run various scripts: prepublish
, preinstall
, install
, postinstall
. Depending on what these scripts do, a npm install
may do considerably more work than just installing dependencies.
I've just had a use case where prepublish
would call make
and the Makefile
was designed to fetch dependencies if the package.json
got updated. Calling npm install
from within the Makefile
would have lead to an infinite recursion, while calling npm update
worked just fine, installing all dependencies so that the build could proceed even if make
was called directly.
npm update
: install and update with latest node modules which are in package.json
npm install
: install node modules which are defined in package.json(without update)
In most cases, this will install the latest version of the module published on npm.
npm install express --save
or better to upgrade module to latest version use:
npm install express@latest --save --force
--save
: Package will appear in your dependencies.
More info: npm-install
npm install installs all modules that are listed on package.json
file and their dependencies.
npm update updates all packages in the node_modules
directory and their dependencies.
npm install express installs only the express module and its dependencies.
npm update express updates express module (starting with [email protected], it doesn't update its dependencies).
So updates are for when you already have the module and wish to get the new version.
Source: Stackoverflow.com