I was going through some documentation and noticed that many developers use this command:
npm install --save
I’m pretty new to Node.js and package management. Can someone explain what the --save flag actually does when you run npm install? I see it used in lots of examples but I’m not sure if I really need it or what happens when I include it versus when I don’t. Does it affect how the package gets installed or where it goes in my project? I want to make sure I understand the basics before I start adding more dependencies to my application.
The --save flag adds the package info straight to your package.json dependencies. Without it, the package installs in node_modules but package.json stays untouched. This breaks things when other devs clone your project or you deploy - they won’t know what packages you need. I learned this the hard way when my deployed app crashed because dependencies weren’t tracked. Newer npm versions do this automatically now, but understanding it helps you get how dependency management works in Node.js.
Back in 2015 when I started with Node.js, I’d constantly forget the --save flag and it drove me crazy. The package would install fine on my machine, but then I’d push to production or share code with teammates and everything would break. Why? Because package.json wasn’t getting updated with the new dependency. My local environment worked great, but production had no clue what packages to install. The --save flag fixes this by automatically adding the package name and version to your package.json. Modern npm does this automatically now, but understanding --save helps you see why package.json is so important for getting the same build across different environments.
the --save flag basically tells npm to add the package to your package.json dependencies. if u don’t use it, you’ll have to manually update package.json - super annoying. but don’t worry, since npm 5, this happens automatically, so it’s not really a biggie now.