Question 1

How do I install NPM packages?

Accepted Answer

Install all dependencies: npm install. Install specific package: npm install package-name. Install specific version: npm install package@1.2.3. Install globally: npm install -g package. Install as dev dependency: npm install --save-dev package (or -D). Clean install from lock file: npm ci (faster, reproducible).

Question 2

What is the difference between npm install and npm ci?

Accepted Answer

npm install: reads package.json, may update lock file, installs missing packages, slower. npm ci: reads lock file only, exact versions, deletes node_modules first, faster, reproducible builds. Use npm install for development, npm ci for CI/CD production builds. npm ci requires lock file to exist.

Question 3

How do I run scripts from package.json?

Accepted Answer

Run scripts: npm run script-name. Common shortcuts: npm test (runs test script), npm start (runs start script), npm build (runs build script). Pass arguments: npm run script -- --arg. View available scripts: npm run (lists all). Scripts defined in package.json scripts section.

Question 4

How do I check for vulnerable NPM packages?

Accepted Answer

Check vulnerabilities: npm audit. Fix automatically: npm audit fix. Fix breaking changes: npm audit fix --force. View detailed report: npm audit --json. Update dependencies: npm update to get patched versions. Use npm audit in CI/CD pipelines for security. Check before publishing packages.

Question 5

What is npx and when should I use it?

Accepted Answer

npx runs npm package executables without installing. Use npx to: run one-time commands (npx create-react-app), run locally installed tools, try packages before installing, execute package binaries. npx downloads package temporarily, runs command, cleans up. Included with npm 5.2+. npx is convenient for CLI tools.

NPM Cheat Sheet

NPM Commands (35)

Common package.json Scripts

NPM vs Yarn vs PNPM