Description: Demonstrating proficiency in Angular 14, 15, 16, 17, 18, 19 involves understanding and applying its new features, creating efficient and scalable web applications, and leveraging Angular's core functionalities to build dynamic user interfaces.
Here’s a breakdown with practical examples:
Angular 14
1. Leveraging Standalone Components
Feature: Angular 14 introduced standalone components to simplify module dependencies.
Example:
Instead of creating a module for every component, you can define a component as standalone:
// product.component.ts
import { Component } from '@angular/core';
import { CommonModule } from '@angular/common';
@Component({
selector: 'app-product',
standalone: true, // Marking as standalone
imports: [CommonModule],
template: `<h1>Product List</h1>`,
})
export class ProductComponent {}
Usage:
You can now directly import this component in your AppModule or routes without wrapping it in a separate module.
// app.module.ts or routes.ts
import { ProductComponent } from './product.component';
@NgModule({
declarations: [],
imports: [BrowserModule, ProductComponent],
bootstrap: [AppComponent],
})
export class AppModule {}
2. Typed Reactive Forms
Feature: Angular 14 added strong typing support for Reactive Forms, reducing errors and improving code maintainability.
Example:
import { Component } from '@angular/core';
import { FormBuilder, FormGroup, Validators, FormControl } from '@angular/forms';
@Component({
selector: 'app-typed-form',
template: `
<form [formGroup]="profileForm">
<label>
Name:
<input formControlName="name" />
</label>
<label>
Age:
<input formControlName="age" type="number" />
</label>
</form>
`,
})
export class TypedFormComponent {
profileForm: FormGroup<{
name: FormControl<string>;
age: FormControl<number>;
}>;
constructor(private fb: FormBuilder) {
this.profileForm = this.fb.group({
name: this.fb.control<string>('', [Validators.required]),
age: this.fb.control<number>(null, [Validators.required, Validators.min(0)]),
});
}
}
3. Route Title Configuration
Feature: Angular 14 allows adding route titles directly in the route configuration.
Example:
import { Routes } from '@angular/router';
import { ProductComponent } from './product.component';
export const routes: Routes = [
{
path: 'products',
component: ProductComponent,
title: 'Product List', // Route title configuration
},
];
The title will automatically update the browser’s title bar when navigating to this route.
4. Optional Injectors in Component APIs
Feature: Angular 14 allows using injectors with ViewContainerRef to create and manage dynamic components more flexibly.
Example:
import {
Component,
Injector,
ViewContainerRef,
createComponent,
} from '@angular/core';
@Component({
selector: 'app-dynamic',
template: `<button (click)="loadComponent()">Load Component</button>`,
})
export class DynamicComponent {
constructor(private viewContainerRef: ViewContainerRef, private injector: Injector) {}
loadComponent() {
const componentRef = createComponent(ProductComponent, {
environmentInjector: this.viewContainerRef.injector,
});
this.viewContainerRef.insert(componentRef.hostView);
}
}
5. Advanced Dependency Injection and Services
Feature: Creating singleton services or scoped services.
Example:
import { Injectable } from '@angular/core';
@Injectable({
providedIn: 'root', // Singleton service at root level
})
export class ApiService {
fetchData() {
return 'Data fetched from API';
}
}
You can also scope services to a specific module or component if needed:
@Injectable({
providedIn: 'any', // Scoped service
})
export class ScopedService {}
Angular 15
1.Directive Composition API
Feature: Allows composing multiple behaviors using directives.
Example:
import { Directive, HostListener } from '@angular/core';
@Directive({
selector: '[appClickTracker]',
})
export class ClickTrackerDirective {
@HostListener('click', ['$event'])
trackClicks(event: Event) {
console.log('Click event tracked!', event);
}
}
// Using this directive
@Component({
selector: 'app-button',
template: `<button appClickTracker>Click Me!</button>`,
})
export class ButtonComponent {}
2.Improved Angular Material Components
Feature: Updated Material components align with the latest Material Design specifications.
Example:
<mat-toolbar color="primary">
<span>Angular App</span>
</mat-toolbar>
<mat-card>
<mat-card-header>
<mat-card-title>Product Card</mat-card-title>
</mat-card-header>
<mat-card-content>
This is an example of an updated Material Design card component.
</mat-card-content>
</mat-card>
Angular 16
#### 1.Signals API (Developer Preview)
Feature: Introduced a reactive state management mechanism for simplicity and performance.
Example:
import { Component, signal } from '@angular/core';
@Component({
selector: 'app-counter',
template: `
<button (click)="increment()">Increment</button>
<p>Count: {{ count() }}</p>
`,
})
export class CounterComponent {
count = signal(0);
increment() {
this.count.set(this.count() + 1);
}
}
Usage: The count() signal updates automatically wherever it's referenced in the template.
2.Hydration for SSR
Feature: Enables hydration for server-rendered applications, allowing smoother client-side rendering.
Example:
This feature is integrated into SSR apps created with Angular Universal. To enable hydration:
import { provideServerRendering } from '@angular/platform-server';
import { provideHydration } from '@angular/platform-browser';
bootstrapApplication(AppComponent, {
providers: [provideServerRendering(), provideHydration()],
});
3.DestroyRef
Feature: Simplifies cleanup for subscriptions and event handlers.
Example:
import { Component, DestroyRef, inject } from '@angular/core';
import { interval } from 'rxjs';
@Component({
selector: 'app-auto-unsubscribe',
template: `<p>Check console for interval logs.</p>`,
})
export class AutoUnsubscribeComponent {
private destroyRef = inject(DestroyRef);
constructor() {
const subscription = interval(1000).subscribe((val) =>
console.log('Interval value:', val)
);
this.destroyRef.onDestroy(() => subscription.unsubscribe());
}
}
Angular 17
1.defer Block
Feature: Optimized lazy loading using defer for parts of the app.
Example:
// dashboard.component.ts
import { Component } from '@angular/core';
@Component({
selector: 'app-dashboard',
template: `<ng-container *defer="loadComponent()"></ng-container>`,
})
export class DashboardComponent {
loadComponent() {
return import('./lazy-feature/lazy-feature.component').then(
(m) => m.LazyFeatureComponent
);
}
}
Usage: Load the LazyFeatureComponent only when needed.
2.Control Flow Syntax
Feature: Enhances conditional rendering with improved syntax.
Example:
@Component({
selector: 'app-user-info',
template: `
<ng-container *if="isLoggedIn; then loggedIn else loggedOut"></ng-container>
<ng-template #loggedIn>Welcome back, User!</ng-template>
<ng-template #loggedOut>Please log in to continue.</ng-template>
`,
})
export class UserInfoComponent {
isLoggedIn = false;
}
3.Final Signals API Release
Feature: Signals API was finalized, making state management seamless.
Example:
import { Component, signal } from '@angular/core';
@Component({
selector: 'app-login-status',
template: `<p>Status: {{ status() }}</p>`,
})
export class LoginStatusComponent {
status = signal('Logged Out');
logIn() {
this.status.set('Logged In');
}
logOut() {
this.status.set('Logged Out');
}
}
Angular 18
1.Module Federation Enhancements
Feature: Improved support for micro-frontends with Module Federation.Enhanced micro-frontend capabilities to allow seamless sharing of code and features across applications.
Example:
Set up Webpack Module Federation to expose or consume remote components:
// webpack.config.js for app1
module.exports = {
plugins: [
new ModuleFederationPlugin({
name: 'app1',
exposes: {
'./Button': './src/app/components/button/button.component.ts',
},
}),
],
};
// Usage in another app (app2)
import('app1/Button').then((module) => {
const Button = module.ButtonComponent;
// Use Button in your app
});
Usage: Share components between app1 and app2 without duplication.
Angular 19
1.Advanced Signals Features
Feature: Enhanced Signals to work with more complex scenarios like derived signals. Expanded capabilities for reactive programming, like derived and computed signals.
Example:
import { Component, signal, computed } from '@angular/core';
@Component({
selector: 'app-shopping-cart',
template: `
<p>Total: {{ total() }}</p>
<button (click)="addItem()">Add Item</button>
`,
})
export class ShoppingCartComponent {
items = signal<number[]>([]);
total = computed(() => this.items().reduce((sum, item) => sum + item, 0));
addItem() {
this.items.set([...this.items(), 10]); // Adding item worth $10
}
}
import { Component, signal, computed } from '@angular/core';
@Component({
selector: 'app-calculator',
template: `
<p>Base: {{ base() }}</p>
<p>Square: {{ square() }}</p>
`,
})
export class CalculatorComponent {
base = signal(5);
square = computed(() => this.base() * this.base());
}
Usage: The total() is a derived signal that updates whenever the items signal changes.
2.Performance Optimizations
Angular 19 continues refining build and runtime performance. The integration is automatic when using ng build with optimizations enabled.
These examples highlight the improvements and practical usage of Angular's evolving features. Each version adds capabilities to make applications more efficient and easier to develop. Let me know if you'd like to dive deeper into any specific version or feature!
Key Takeaway:
Proven expertise with Angular 14+ requires not only familiarity with these features but also the ability to apply them effectively in real-world scenarios. Highlight how you’ve used these new capabilities to solve complex challenges in your projects during the interview.
Check this blog: Comprehensive Angular Interview Questions and Answers🚀
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