Top 10 Angular Interview Questions

Overview

This guide provides a structured approach to understanding common Angular interview questions. It aims to equip candidates with the knowledge and insights necessary to effectively demonstrate their expertise in Angular development. The questions cover core concepts, architectural patterns, and practical application of the framework.

Interview Rounds

The interview questions are designed to assess a candidate's understanding across various aspects of Angular.

Question 1: What is Angular, and how is it different from AngularJS?

• Objective: Evaluates the candidate's understanding of the evolution of Angular and its key differences from its predecessor, AngularJS.
• Expected Answer Insight: Angular is a TypeScript-based, component-based framework and a complete rewrite of AngularJS (a JavaScript-based MVC framework). Key differences include improved performance, modularity, and dependency injection. Emphasis should be placed on the shift to reactive programming using RxJS.

Question 2: Explain Angular's architecture.

• Objective: Assesses the candidate's knowledge of the fundamental building blocks of an Angular application.
• Expected Answer Insight: Angular architecture is built upon modules (NgModule), components, templates, services, and directives. Modules group components into functional blocks. Components define the view and interact with services for logic.

Question 3: What is the difference between ngOnInit() and a constructor?

• Objective: Determines the candidate's understanding of Angular lifecycle hooks.
• Expected Answer Insight: The constructor is a TypeScript feature for dependency injection and initialization. ngOnInit() is an Angular lifecycle hook called after Angular initializes the component's data-bound properties.

Question 4: How does data binding work in Angular?

• Objective: Gauges the candidate's familiarity with data binding techniques in Angular.
• Expected Answer Insight: Angular supports four types of data binding: Interpolation (one-way: component to template), Property Binding (one-way: DOM properties), Event Binding (handling events), and Two-Way Binding ([(ngModel)]: data sync between template and component).