10+ Siemens Front end Developer Interview Questions and Answers

Sort an array of positive integers (0, 1, 2) in non-decreasing order.

• Use counting sort algorithm to sort the array efficiently.

• Count the occurrences of 0s, 1s, and 2s in the array.

• Update the array with the counts of each element in non-decreasing order.

Components are building blocks of Angular applications, while directives are used to add behavior to DOM elements.

• Components have a template, styles, and behavior encapsulated together, while directives are used to manipulate the behavior of existing DOM elements.

• Components are typically used to create reusable UI elements, while directives are used to add custom behavior to existing elements.

• Components can have their own view encapsulation, while directives do not have their...read more

var is function scoped while let is block scoped in JavaScript.

• var is function scoped, meaning it is accessible throughout the function it is declared in.

• let is block scoped, meaning it is only accessible within the block it is declared in.

• Using var can lead to variable hoisting issues, while let avoids this problem.

• Example: var x = 10; function test() { var x = 20; console.log(x); } test(); // Output: 20

Prototype chaining in JavaScript is the mechanism by which objects inherit properties and methods from other objects.

• In JavaScript, each object has a prototype property that points to another object. When a property or method is accessed on an object, JavaScript will look for it in the object itself first, and then in its prototype chain.

• If the property or method is not found in the object, JavaScript will continue to look up the prototype chain until it finds the property or...read more

HTML5 is the latest version of the HTML standard with new features for web development.

• Support for multimedia elements like <video> and <audio>

• Canvas and SVG for graphics and animations

• Improved form controls and validation

• Offline storage with Local Storage and IndexedDB

• Geolocation API for location-based services

Hoisting in JavaScript is a behavior where variable and function declarations are moved to the top of their containing scope during the compilation phase.

• Variable declarations are hoisted to the top of their scope, but not their assignments.

• Function declarations are fully hoisted, meaning they can be called before they are declared.

• Hoisting can lead to unexpected behavior if not understood properly.

The CSS Box Model is a fundamental concept in CSS that defines the layout and spacing of elements on a webpage.

• The Box Model consists of content, padding, border, and margin.

• Content: The actual content or text of the element.

• Padding: Space between the content and the border.

• Border: The border surrounding the padding and content.

• Margin: Space outside the border, separating the element from other elements.

• Example: div { width: 200px; padding: 20px; border: 1px solid black; marg...read more

Dependency injection in Angular is a design pattern where components are given their dependencies rather than creating them themselves.

• In Angular, dependency injection is achieved by declaring the dependencies in the constructor of a component or service.

• It helps in making components more modular, reusable, and easier to test.

• For example, if a component needs a service to fetch data from an API, instead of creating an instance of the service within the component, the service ...read more

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

• Lifecycle hooks include ngOnInit, ngOnChanges, ngDoCheck, ngOnDestroy, etc.

• ngOnInit is used for initialization logic, ngOnChanges for reacting to input changes, ngDoCheck for custom change detection, ngOnDestroy for cleanup tasks, etc.

Closures in JavaScript are functions that have access to variables from their outer scope even after the outer function has finished executing.

• Closures allow for maintaining state in JavaScript functions.

• They are created whenever a function is defined within another function.

• Closures can access variables from their outer scope, even after the outer function has finished executing.

Components in Angular are reusable building blocks that encapsulate HTML, CSS, and TypeScript logic.

• Components are the basic building blocks of Angular applications.

• They consist of an HTML template, CSS styles, and TypeScript code.

• Components help in organizing the application into smaller, reusable pieces.

• They can communicate with other components using @Input and @Output decorators.

• Example: A 'navbar' component can be created to display navigation links across the applicatio...read more

A service in Angular is a reusable piece of code that can be injected into components to provide specific functionality.

• Services are singleton objects in Angular that are instantiated only once during the lifetime of an application.

• They are used to encapsulate logic and data that can be shared across multiple components.

• Services can be injected into components, directives, and other services using Angular's dependency injection system.

• Examples of services in Angular include H...read more