Full Stack Interview Questions and Answers- Part 4

Answer:

There are many advantages of unit tests in software development:

• It improves the code quality and makes the process agile.
• Refactoring code becomes easier through unit testing.
• It helps developers in creating better designs.
• Helps in finding software bugs earlier. Since unit testing helps remove bugs early, it helps reduce the cost of fixing bugs.
• Unit testing provides documentation of the system to developers working on the projects.

Answer:

Safeguarding data within applications is vital for upholding the confidentiality of sensitive information, maintaining credibility, adhering to legal guidelines, and preventing financial harm. To ensure data security during the application development process, a number of strategies can be employed:

• Utilize secure coding techniques: Construct applications using secure coding methodologies like input validation, access management, and proficient error handling.
• Apply encryption to data in motion and at rest: Employ encryption protocols to safeguard data both during transit and while it’s stored in databases. This measure is effective in thwarting unauthorized access and data breaches.
• Establish robust authentication mechanisms: Implement sturdy authentication procedures to ensure that only authorized people get access to confidential data.
• Conduct regular security assessments: Undertake routine security evaluations, encompassing vulnerability scans and penetration tests, to proactively detect and rectify potential security vulnerabilities before they can be manipulated.
• Adhere to industry best practices: Adherence to established industry best practices, including organizational directives and governmental regulations, plays a pivotal role in guaranteeing the security, efficiency, and sustainability of your applications.

Answer:

Unit testing is a software testing technique focused on examining individual components or modules, typically performed during development. Its purpose is to identify and address errors within the smallest code units early in the development process. On the other hand, integration testing involves assessing the behavior of multiple units or components when combined. The primary goal of integration testing is to verify the correct functioning of these individual components when they interact.

Answer:

Microservices architecture is a design principle for constructing applications using small, independent, and loosely interconnected services. Each service concentrates on specific business functionalities and can be created, evaluated, and deployed autonomously. This approach enhances scalability, resilience, and accelerates development cycles. However, it introduces complexities in areas such as inter-service communication, coordination, and data synchronization.

Answer:

The CSS box model is a foundational concept governing the visual layout of elements within a webpage. It comprises four core components: content, padding, border, and margin. The content section accommodates text or images. Padding is the space between content and the element’s border. The border is a visual boundary surrounding the padding, while the margin designates the gap between the border and the surrounding elements. These constituents collectively contribute to the overall size and arrangement of an element, crucial for effective web design.

Answer:

Lazy loading within Angular refers to a performance optimization strategy where components or modules are loaded on-demand instead of upfront. This tactic aids in enhancing the app’s speed and efficiency. It’s especially beneficial for larger applications housing numerous modules and components, as it allows developers to split the application into smaller segments and load them only when needed.

Answer:

Developing a project from scratch requires a range of skills and technologies, including:

• Proficiency in frontend technologies like HTML, CSS, JavaScript, and frameworks such as Angular or ReactJS.
• Design expertise encompassing UX/UI principles for creating user-friendly interfaces.
• Strong grasp of backend programming languages like Java, Python, PHP, etc.
• Familiarity with relevant frameworks like Spring Boot, Django, or Ruby on Rails for efficient development.
• Competence in handling database technologies such as MySQL, Oracle, MongoDB, etc.
• Knowledge of server administration, involving servers like Apache or NGINX, for deployment and management.

Answer:

In PHP, the “extract” function is used to import variables from an array into the local symbol table. This makes it possible to access array values as separate variables, simplifying code readability. However, caution must be exercised when using “extract,” as improper usage can lead to naming conflicts within the codebase.

Answer:

The “alt” attribute is employed for images in HTML to provide an alternative description when the image is not displayed or can’t be seen by the user. This description offers contextual information about the image’s content, serving as a fallback in cases where the image isn’t visible due to factors like slow internet connection or errors in loading.

Answer:

HashMap and Hashtable are both used to store key-value pairs, but they have notable distinctions:

HashMap is not synchronized, making it thread-unsafe and inappropriate for shared use across multiple threads without additional synchronization. Hashtable, in contrast, is synchronized and designed for thread-safe operation.

HashMap permits one null key and multiple null values. Hashtable does not allow null keys or values.

In scenarios where thread synchronization is unnecessary, HashMap is generally favored over Hashtable for its more efficient performance.

Answer:

A Java applet is a compact, executable program that is intended to run within a web browser. Applets are used to enhance webpages by adding interactivity and dynamic content. They can be embedded into HTML pages using the APPLET or OBJECT tag and are executed within the Java Virtual Machine (JVM) present on the user’s system.

Answer:

In AngularJS, the term “Scope” refers to a JavaScript object that serves as the bridge between the view (HTML) and the controller (JavaScript) components of an application. It acts as a data container and carries application data, as well as methods that are specific to a certain part of the application. The scope facilitates the synchronization of data between the view and the controller, enabling dynamic updates and interaction.

Answer:

V8 is an open-source JavaScript engine developed by Google, primarily implemented in C++. It executes JavaScript code and adheres to the ECMAScript specification. It provides the runtime environment for running JavaScript applications outside of a web browser. V8 is notably used in the Google Chrome browser and the Node.js runtime, contributing to their efficiency and performance.

Answer:

WebP is a contemporary image format devised by Google. It employs both lossy and lossless compression methods to generate smaller image files while retaining high visual quality. This format is advantageous for web content as it reduces page loading times, enhancing user experience. WebP images are typically 25-34% smaller than images in formats like PNG or JPEG.

Answer:

In React, “State” is an inherent object that stores mutable data within a component. It represents values that can change over time, often due to user interactions or system events. Components can use state to manage and track dynamic information, and when state changes, the component typically re-renders to reflect the updated data.

Answer:

jQuery is a lightweight and speedy JavaScript library created to streamline web development using JavaScript. Its features encompass:

• HTML/DOM manipulation
• Cross-browser compatibility
• CSS manipulation
• HTML event methods
• Effects and animations
• AJAX support
• Extensive collection of plugins

Answer:

In C#, a namespace is a mechanism for logically grouping related classes, types, and other members together. It provides a way to organize code and avoid naming conflicts. Namespaces enable developers to create modular and organized codebases, making it easier to manage and understand complex applications.

Answer:

Hoisting is a behavior in JavaScript where variable and function declarations are moved to the top of their scope during the compilation phase. This allows you to use these variables and functions before they are formally declared in the code. However, only declarations are hoisted, not initializations, so it’s important to be aware of this behavior.

Answer:

Backtracking is an algorithmic approach used to solve problems by systematically trying out different possibilities and making incremental adjustments to reach a solution. It’s often employed for decision, optimization, and enumeration problems. Backtracking helps in searching through a vast solution space efficiently, pruning unfruitful branches and arriving at the correct solution.

Answer:

Double brace initialization is a technique used in Java for creating and initializing instances of anonymous inner classes in a concise manner. The first set of braces define an anonymous inner class, while the second set contains instance initialization code.

Advantages of double brace initialization include:

• Conciseness: It reduces the need for multiple lines of code.
• Readability: It enhances code clarity by combining object creation and initialization.
• Inline Initialization: Both class definition and instance initialization occur in a single expression.