install package in devdependencies code example

Example 1: npm dev dependencies

# install as devDependency
npm install  --save-dev

# install as normal dependency
npm install  --save

# install all devDependencies listed in package.json
npm install --only=dev

# install all normal dependencies listed in package.json
npm install --only=prod
# or if NODE_ENV is set to production
npm install

Example 2: npm install package as developer dependency

npm install --save-dev package
# example:
npm install --save-dev nodemon