What is the Angular RouterModule
💡 Concept Name
Angular RouterModule – A built-in Angular module that enables navigation and URL routing in single-page applications (SPAs) using path-to-component mappings.
📘 Quick Intro
The RouterModule is part of the Angular Router library that allows developers to define routes and configure navigation across components in a SPA without full page reloads.
🧠 Analogy / Short Story
Think of RouterModule as a GPS system in a car. It tells your Angular app which “road” (URL path) to take to reach a “destination” (component view) — all without restarting the engine (reloading the page).
🔧 Technical Explanation
- 🧩 RouterModule provides directives like
routerLinkandrouter-outlet. - 🛣️ Configured using
RouterModule.forRoot(routes)in root module andforChildin feature modules. - 🔄 Handles route matching, navigation events, and guards.
- 🚧 Allows lazy loading of feature modules.
- 🧪 Enables parameterized routing and query params.
🎯 Purpose & Use Case
- ✅ Navigation between components in SPAs.
- ✅ Implementing route guards and access control.
- ✅ Lazy loading modules on demand to optimize performance.
- ✅ Supporting deep linking and bookmarking in Angular apps.
💻 Real Code Example
// app-routing.module.ts
import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';
import { HomeComponent } from './home/home.component';
import { AboutComponent } from './about/about.component';
const routes: Routes = [
{ path: '', component: HomeComponent },
{ path: 'about', component: AboutComponent }
];
@NgModule({
imports: [RouterModule.forRoot(routes)],
exports: [RouterModule]
})
export class AppRoutingModule { }
<!-- app.component.html -->
<nav>
<a routerLink="/">Home</a>
<a routerLink="/about">About</a>
</nav>
<router-outlet></router-outlet>
❓ Interview Q&A
Q1: What is the role of RouterModule in Angular?
A: It enables route configuration and navigation in SPAs.
Q2: What is the difference between forRoot and forChild?
A: forRoot is used in the root module; forChild is used in feature modules.
Q3: How do you define routes using RouterModule?
A: By passing a route configuration array to RouterModule.forRoot().
Q4: Which directive is used to create navigation links?
A: routerLink.
Q5: What does <router-outlet> do?
A: Acts as a placeholder for displaying routed components.
📝 MCQs
Q1. What module enables routing in Angular?
- FormsModule
- BrowserModule
- RouterModule
- CommonModule
Q2. What directive loads routed components?
- ng-view
- router-outlet
- ng-template
- router-slot
Q3. What does routerLink bind to?
- Component
- Function
- A path in route configuration
- Form
Q4. How do you configure routes in root module?
- RouterModule.use()
- RouterModule.set()
- RouterModule.forRoot()
- RouterModule.register()
Q5. Which allows feature module routing?
- RouterModule.forFeature()
- RouterModule.forChild()
- RouterModule.create()
- RouterModule.module()
Q6. What is the main benefit of RouterModule?
- Backend routing
- Client-side navigation in SPA
- Database sync
- SEO improvement
Q7. What happens if a route is not matched?
- Page reloads
- Nothing
- Fallback or 404 route is activated
- Navigation loops
Q8. What is a nested route?
- Duplicate route
- Route to service
- Route inside a parent route
- Lazy module
Q9. What Angular file usually contains routes?
- index.ts
- main.ts
- app-routing.module.ts
- style.css
Q10. What does RouterModule export?
- Global styles
- Data pipes
- Routing directives like routerLink
- Component schema
💡 Bonus Insight
Angular’s RouterModule also supports navigation lifecycle events, guards like CanActivate, wildcard routes for 404s, and preloading strategies to optimize performance of lazy-loaded routes.
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