docs: remove empty constructors & ngOnInit() (angular#48576)

PR Close angular#48576

Author: JeanMeche

aio/content/examples/property-binding/src/app/item-detail/item-detail.component.ts

@@ -7,7 +7,7 @@ import { Component, OnInit, Input } from '@angular/core';
   templateUrl: './item-detail.component.html',
   styleUrls: ['./item-detail.component.css']
 })
-export class ItemDetailComponent implements OnInit {
+export class ItemDetailComponent {
 
   // #docregion input-type
   @Input() childItem = '';
@@ -18,9 +18,4 @@ export class ItemDetailComponent implements OnInit {
 
   currentItem = 'bananas in boxes';
 
-  constructor() { }
-
-  ngOnInit() {
-  }
-
 }

aio/content/examples/property-binding/src/app/item-list/item-list.component.ts

@@ -12,6 +12,5 @@ export class ItemListComponent {
   // #docregion item-input
   @Input() items: Item[] = [];
   // #enddocregion item-input
-  constructor() { }
 
 }

aio/content/examples/two-way-binding/src/app/app.component.ts

@@ -6,7 +6,6 @@ import { Component } from '@angular/core';
   styleUrls: ['./app.component.css']
 })
 export class AppComponent {
-  constructor() { }
   // #docregion font-size
   fontSizePx = 16;
   // #enddocregion font-size

aio/content/examples/upgrade-lazy-load-ajs/src/app/home/home.component.ts

@@ -1,15 +1,10 @@
-import { Component, OnInit } from '@angular/core';
+import { Component } from '@angular/core';
 
 @Component({
   selector: 'app-home',
   templateUrl: './home.component.html',
   styleUrls: ['./home.component.css']
 })
-export class HomeComponent implements OnInit {
-
-  constructor() { }
-
-  ngOnInit() {
-  }
+export class HomeComponent {
 
 }

aio/content/start/start-data.md

@@ -115,9 +115,6 @@ For customers to see their cart, you can create the cart view in two steps:
 
     <code-example header="src/app/cart/cart.component.ts" path="getting-started/src/app/cart/cart.component.1.ts"></code-example>
 
-    StackBlitz also generates an `ngOnInit()` by default in components.
-    You can ignore the `CartComponent` `ngOnInit()` for this tutorial.
-
 1.  Notice that the newly created `CartComponent` is added to the module's `declarations` in `app.module.ts`.
 
     <code-example header="src/app/app.module.ts" path="getting-started/src/app/app.module.ts" region="declare-cart"></code-example>