What is the –save option for npm install? – Dev

The best answers to the question “What is the –save option for npm install?” in the category Dev.

QUESTION:

I saw some tutorial where the command was:

npm install --save

What does the --save option mean?

Not able to find the answer on Google.

ANSWER:

Update as of npm 5:

As of npm 5.0.0, installed modules are added as a dependency by default, so the –save option is no longer needed. The other save options still exist and are listed in the documentation for npm install.


Original Answer:

To add package in dependencies:

npm install my_dep --save

or

npm install my_dep -S

or

npm i my_dep -S

To add package in devDependencies

npm install my_test_framework --save-dev

or

npm install my_test_framework -D

or

npm i my_test_framework -D

package.json
enter image description here

ANSWER:

Update npm 5:

As of npm 5.0.0, installed modules are added as a dependency by default, so the --save option is no longer needed. The other save options still exist and are listed in the documentation for npm install.

Original answer:

Before version 5, NPM simply installed a package under node_modules by default. When you were trying to install dependencies for your app/module, you would need to first install them, and then add them (along with the appropriate version number) to the dependencies section of your package.json.

The --save option instructed NPM to include the package inside of the dependencies section of your package.json automatically, thus saving you an additional step.

In addition, there are the complementary options --save-dev and --save-optional which save the package under devDependencies and optionalDependencies, respectively. This is useful when installing development-only packages, like grunt or your testing library.

ANSWER:

according to NPM Doc

enter image description here

So it seems that by running npm install package_name, the package dependency should be automatically added to package.json right?

ANSWER:

Update as of npm 5:

As of npm 5.0.0, installed modules are added as a dependency by default, so the –save option is no longer needed. The other save options still exist and are listed in the documentation for npm install.


Original answer:

It won’t do anything if you don’t have a package.json file. Start by running npm init to create one. Then calls to npm install --save or npm install --save-dev or npm install --save-optional will update the package.json to list your dependencies.