added page not found wildcard route

src/app/app-routing.module.ts

@@ -1,6 +1,7 @@
 import { NgModule } from '@angular/core';
 import { RouterModule, Routes } from '@angular/router';
 import { WelcomeComponent } from './core-components/welcome/welcome.component';
+import { PageNotFoundComponent } from './core-components/page-not-found/page-not-found.component';
 
 const routes: Routes = [
   {
@@ -11,7 +12,10 @@ const routes: Routes = [
   {
     path: 'welcome',
     component: WelcomeComponent
-  }
+  },
+  //wildcard/page not found needs to be last route
+  //triggered after entire route tree is checked
+  { path: "**", component: PageNotFoundComponent },
 
 ];
 

src/app/app.module.ts

@@ -5,12 +5,14 @@ import { AppRoutingModule } from './app-routing.module';
 import { AppComponent } from './app.component';
 import { NavbarComponent } from './core-components/navbar/navbar.component';
 import { WelcomeComponent } from './core-components/welcome/welcome.component';
+import { PageNotFoundComponent } from './core-components/page-not-found/page-not-found.component';
 
 @NgModule({
   declarations: [
     AppComponent,
     NavbarComponent,
-    WelcomeComponent
+    WelcomeComponent,
+    PageNotFoundComponent
   ],
   imports: [
     BrowserModule,

src/app/core-components/page-not-found/page-not-found.component.html

@@ -0,0 +1,15 @@
+<div class="row justify-content-center pt-3">
+    <div class="card col-lg-6 col-sm-10">
+        <div class="card-body">
+            <div class="card-title display-4">
+                404 Page Not Found
+            </div>
+            <p class="card-text">
+                We weren't able to find the page you were looking for. Please return to the dashboard by clicking the
+                button below.
+            </p>
+            <hr>
+            <button class="btn btn-primary" routerLink="/">Back to Dashboard</button>
+        </div>
+    </div>
+</div>

src/app/core-components/page-not-found/page-not-found.component.spec.ts

@@ -0,0 +1,21 @@
+import { ComponentFixture, TestBed } from '@angular/core/testing';
+
+import { PageNotFoundComponent } from './page-not-found.component';
+
+describe('PageNotFoundComponent', () => {
+  let component: PageNotFoundComponent;
+  let fixture: ComponentFixture<PageNotFoundComponent>;
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({
+      declarations: [PageNotFoundComponent]
+    });
+    fixture = TestBed.createComponent(PageNotFoundComponent);
+    component = fixture.componentInstance;
+    fixture.detectChanges();
+  });
+
+  it('should create', () => {
+    expect(component).toBeTruthy();
+  });
+});

src/app/core-components/page-not-found/page-not-found.component.ts

@@ -0,0 +1,10 @@
+import { Component } from '@angular/core';
+
+@Component({
+  selector: 'app-page-not-found',
+  templateUrl: './page-not-found.component.html',
+  styleUrls: ['./page-not-found.component.css']
+})
+export class PageNotFoundComponent {
+
+}