Bootstrap 4 has two dependencies: jQuery 1.9.1 and popper.js 1.12.3. When you install Bootstrap 4, you need to install these two dependencies.
- Install popper.js:
npm install popper.js@^1.12.3 --save
- Install jQuery:
npm install jquery@1.9.1 --save
- Install Bootstrap:
npm install bootstrap@4.0.0-beta.2 --save
For Bootstrap 4.1
npm install popper.js@^1.14.3 --save
npm install jquery@3.3.1 --save
npm install bootstrap@4.1.1 --save