check ionic version code example

Example 1: ionic cli

$ npm install -g @ionic/cli

Example 2: ionic project version

you can always do npm list ionic-angular should give you the version 
of ionic you project is using

Example 3: how to check app version in ionic

import { AppVersion } from '@ionic-native/app-version/ngx';

constructor(private appVersion: AppVersion) { }

...


this.appVersion.getAppName();
this.appVersion.getPackageName();
this.appVersion.getVersionCode();
this.appVersion.getVersionNumber();