10+ TCS Angular Developer Interview Questions and Answers

A set of questions related to JavaScript and Angular for an Angular Developer interview.

• let vs var: let is block-scoped while var is function-scoped

• shallow copy vs deep copy: Shallow copy creates a new reference to the original object, while deep copy creates a new object with its own copy of all nested objects

• timeout: Used to delay the execution of a function or code block for a specified amount of time

• Pipes: Used for transforming data in Angular templates

• Dependency Injectio...read more

Normal functions are defined using the function keyword, while arrow functions are defined using the => syntax.

• Normal functions are hoisted, while arrow functions are not.

• Arrow functions do not have their own 'this' keyword, they inherit it from the parent scope.

• Arrow functions are more concise and have implicit return.

• Arrow functions cannot be used as constructors.

• Arrow functions are not suitable for methods within objects due to the lack of their own 'this'.

Strict operator (!) is used to check if a value is truthy or falsy. Rest operator (...) is used to collect multiple arguments into an array.

• Strict operator (!) checks if a value is truthy or falsy, for example: if (!value) { // do something }

• Rest operator (...) collects multiple arguments into an array, for example: function sum(...args) { return args.reduce((acc, val) => acc + val, 0); }

ES6 features are modern JavaScript syntax enhancements introduced in ECMAScript 2015.

• Arrow functions for concise syntax: const add = (a, b) => a + b;

• Let and const for block-scoped variables: let x = 5; const y = 10;

• Template literals for string interpolation: const name = 'Alice'; console.log(`Hello, ${name}!`);

• Classes for object-oriented programming: class Person { constructor(name) { this.name = name; } }

• Destructuring for easy assignment: const { a, b } = { a: 1, b: 2 };

• Spre...read more

Services are used to share data or functionality across components in Angular.

• Services are singleton objects that can be injected into components.

• They can be used to share data between components.

• They can also be used to encapsulate and share functionality.

• Examples include HTTP service for making API calls and logging service for tracking user actions.

Components are building blocks of Angular applications. Data can be shared between components using input/output properties, services, or state management. Pipes are used for data transformation in templates.

• Components are reusable, self-contained units of code that define the view and behavior of a part of the application.

• Data can be shared between components using @Input and @Output properties for parent-child communication, services for cross-component communication, or st...read more

Data can be passed from one component to another in Angular using @Input, @Output, services, and routing.

• Use @Input to pass data from parent to child component

• Use @Output to emit events from child to parent component

• Use services to share data between components

• Use routing to pass data between components using route parameters or query parameters

Angular lifecycle hooks are methods that allow you to tap into specific points in a component's lifecycle.

• ngOnChanges

• ngOnInit

• ngDoCheck

• ngAfterContentInit

• ngAfterContentChecked

• ngAfterViewInit

• ngAfterViewChecked

• ngOnDestroy

Angular bootstrapping process initializes the Angular application by loading the root module and compiling the component templates.

• Angular application is bootstrapped by calling the 'platformBrowserDynamic().bootstrapModule()' method in the main.ts file.

• The 'AppModule' is typically the root module of the Angular application.

• During bootstrapping, Angular creates the component tree, compiles the component templates, and starts the application.

Types of data binding in Angular include one-way binding, two-way binding, and event binding.

• One-way binding: Data flows in one direction from the component class to the template. Example: {{ data }}

• Two-way binding: Data flows in both directions between the component class and the template. Example: [(ngModel)]

• Event binding: Allows you to listen for and respond to user events in the template. Example: (click)

JavaScript array methods are built-in functions that manipulate arrays.

• Some common array methods are push(), pop(), shift(), unshift(), slice(), splice(), concat(), join(), and sort().

• push() adds an element to the end of an array.

• pop() removes the last element from an array.

• shift() removes the first element from an array.

• unshift() adds an element to the beginning of an array.

• slice() returns a new array with a portion of the original array.

• splice() adds or removes elements fro...read more

NgViewInit() is a lifecycle hook method in Angular that is called after the component's view has been fully initialized.

• NgViewInit() is used to perform tasks that require the view to be fully initialized, such as initializing data-bound properties or setting up event listeners.

• It is commonly used to fetch data from a backend API and update the view accordingly.

• Example: ngOnInit() { this.http.get('api/data').subscribe(data => { this.data = data; }); }

Angular is a popular open-source web application framework developed by Google for building dynamic single-page applications.

• Angular is based on TypeScript, a superset of JavaScript.

• It uses a component-based architecture for building UI elements.

• Angular provides features like data binding, dependency injection, and routing.

• It has a powerful CLI for scaffolding and managing projects.

• Angular is commonly used for building interactive web applications.