As Now, angular 5 has been released officially on 1st Novemebr 2017,
So for those who want to update your old angular applications to angular 5:
1) The Angular team has also put a handy tool to make upgrading from any version to angular 5, as simple as possible.
2) You will have to upgrade all of your angular packages to version 5.0, run the following command:
npm install @angular/animations@^5.0.0 @angular/common@^5.0.0 @angular/compiler@^5.0.0 @angular/compiler-cli@^5.0.0 @angular/core@^5.0.0 @angular/forms@^5.0.0 @angular/http@^5.0.0 @angular/platform-browser@^5.0.0 @angular/platform-browser-dynamic@^5.0.0 @angular/platform-server@^5.0.0 @angular/router@^5.0.0 zone.js@^0.8.4 @angular/upgrade@^5.0.0 typescript@2.4.2 rxjs@^5.5.2
3) Angular 5 now also depends on TypeScript 2.4.2 and RxJS 5.5.2, so you’ll have to upgrade those package as well.
npm install typescript@2.4.2 --save-exact
4) If you rely on the date, currency, decimal, or percent pipes, in 5 you will see minor changes to the format. For applications using locales other than en-us you will need to import it and optionally locale_extended_fr from @angular/common/i18n_data/locale_fr and registerLocaleData(local).
For more information on pipes breaking changes:
https://stackoverflow.com/a/47263949/2810015
5) Use of implements instead of extends with any lifecycle events : Ensure you don’t use extends OnInit, or use extends with any lifecycle event. Instead use implements .
6) Switch from HttpModule and the Http service to HttpClientModule and the HttpClient service. HttpClient simplifies the default ergonomics (You don’t need to map to json anymore and remove any map(res => res.json()) calls, which are no longer needed.) and now supports typed return values and interceptors.
7) The recommended way of importing operators in RxJS 5.5 is from rxjs/operators.
import { map, filter, mergeMap, tap } from 'rxjs/operators';
I have tried to explain more here.
https://onlyforcoder.blogspot.in/2017/11/angular-5-upgrade-your-project-To-Angular5.html