Ionic 4 Expert

Ionic v4 (released 2019) was a complete rewrite of Ionic v3. The key architectural shifts:

• Web components via Stencil — ion-* elements work in any framework or vanilla JS
• Framework-agnostic — Angular (primary), React, Vue, or plain HTML
• Navigation changed — from v3's NavController push/pop stack → Angular Router + <ion-router-outlet>
• CSS custom properties replace SASS variables for theming
• Capacitor introduced as the modern alternative to Cordova

Most Ionic v4 projects use Angular. This skill assumes Angular unless stated otherwise.

Architecture