Feature modules for organization in Angular - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

How does lazy loading a feature module affect the initial app load?

Consider an Angular app with a feature module set up for lazy loading. What happens to the app's initial load time when this feature module is lazy loaded?

A The app will fail to load because lazy loading requires special server configuration.

B The initial load time increases because lazy loading adds extra overhead during startup.

C The initial load time stays the same because all modules are bundled together regardless of lazy loading.

D The initial load time decreases because the feature module code is loaded only when needed.

💡 Hint

Think about when the feature module's code is downloaded by the browser.

Lazy loading delays loading the feature module until it is needed, reducing the initial bundle size and improving startup speed.

📝 Syntax

intermediate

Identify the correct way to declare a feature module in Angular

Which of the following code snippets correctly declares a feature module named AdminModule?

Angular

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { AdminComponent } from './admin.component';

A @NgModule({ declarations: [AdminComponent], imports: [CommonModule] }) export class AdminModule {}

B @Module({ declarations: [AdminComponent], imports: [CommonModule] }) export class AdminModule {}

C @NgModule({ components: [AdminComponent], imports: [CommonModule] }) export class AdminModule {}

D NgModule({ declarations: [AdminComponent], imports: [CommonModule] }) export class AdminModule {}

💡 Hint

Look for the correct decorator syntax and property names.

The @NgModule decorator is required with the declarations and imports properties. The decorator must be prefixed with '@'.

❓ lifecycle

advanced

When is a feature module's constructor executed in Angular?

In an Angular app, when does the constructor of a feature module class run?

A When the app starts, before any components load.

B Only when the feature module is loaded, either eagerly or lazily.

C Every time a component inside the feature module is created.

D Only when the root module finishes loading.

💡 Hint

Think about when Angular loads the module code.

The feature module's constructor runs when Angular loads the module, which happens eagerly at startup or lazily when the user navigates to it.

🔧 Debug

advanced

Why does importing a feature module twice cause an error?

Given two feature modules both importing the same shared feature module, what problem can occur and why?

A Angular throws a compile-time error because duplicate module imports are not allowed.

B Angular merges the modules silently, so no error occurs.

C Angular throws a runtime error because the shared module's services are instantiated twice causing conflicts.

D Angular ignores the second import and uses the first one without error.

💡 Hint

Consider how Angular handles services provided in modules.

Importing a shared module multiple times can cause multiple instances of services if the module provides them, leading to unexpected behavior and runtime errors.

🧠 Conceptual

expert

What is the main benefit of organizing an Angular app with feature modules?

Why do Angular developers use feature modules to organize their apps instead of putting all components and services in the root module?

A Feature modules help split the app into focused areas, improving maintainability and enabling lazy loading for better performance.

B Feature modules allow Angular to skip change detection in those parts of the app.

C Feature modules automatically make the app run faster by compiling code differently.

D Feature modules are required to use Angular Material components.

💡 Hint

Think about how breaking code into smaller parts helps developers and users.

Feature modules organize code into logical groups, making it easier to manage and allowing lazy loading to improve app startup time.