Important Notice— Our url is 
Full Stack Interview Questions and Answers- Part 9
The tech industry is growing fast, and full stack developers are in high demand. These professionals know how to build and manage every part of a website or application. But getting hired for a full stack role isn’t easy—it takes strong technical knowledge and good interview preparation. That’s why we’ve created this list of full stack interview questions and answers.
These questions focus on the most important topics you’ll need to know for your interview. We cover HTML, CSS, JavaScript, front-end frameworks, server-side tools, and database systems. All answers are explained in a clear and simple way, so you can understand and remember them easily. This blog is a great tool for anyone who wants to feel more prepared and confident.
Answer:
The CSS Box Model stands as a foundational concept within Cascading Style Sheets, serving as a fundamental framework for designing webpage layouts. This model entails a container that encompasses several essential properties—namely margin, padding, border, and the content area. Each of these components contributes to the spatial arrangement and appearance of an element. When rendering a webpage, the web browser adheres to the CSS Box Model, representing each element as a rectangular box and applying the associated properties accordingly.
In CSS, the Box Model encompasses various key properties:
- Content: This attribute pertains to the presentation of textual content, images, and other elements. The dimensions of the content can be tailored using properties such as width and height.
- Padding: Padding designates the space between an element’s content and its border. It furnishes an internal spacing that separates content from the border. Utilizing the padding property, one can define the size of this internal spacing.
- Border: The border property determines the style, color, and width of the border encircling an element’s content and padding. This visual boundary demarcates the element from its neighboring elements. By manipulating the border property, diverse border styles can be achieved.
- Margin: Margin signifies the space between an element’s border and the surrounding elements. It creates a gap or buffer that segregates elements. Adjusting the margin property influences the size of this spacing.
Answer:
CSS selectors facilitate the precise targeting of specific HTML elements for styling purposes. Within CSS, selectors encompass distinct categories that offer flexibility in selecting elements:
Simple Selectors: These selectors pinpoint elements based on factors like their tag name, class, ID, or attributes. For instance:
- Tag Selector: p selects all elements.
- Class Selector: .classname targets elements with the specified class.
- ID Selector: #idname focuses on the element with the designated ID.
- Attribute Selector: [attribute=value] singles out elements with the specified attribute and value.
Combinator Selectors: These selectors identify elements based on their relationships with other elements. Various types of combinators include:
- Descendant Selector: A B selects all B elements that are descendants of A.
- Child Selector: A > B picks out B elements that are direct children of A.
- Adjacent Sibling Selector: A + B highlights the B element that immediately follows A.
- General Sibling Selector: A ~ B chooses all B elements that are siblings of A.
Pseudo-Class Selectors: These selectors target elements based on their specific states.
Answer:
An HTML table is structured as an arrangement of rows and columns, defined using the table tag. Within an HTML document, different types of tags are interconnected with the table tag to create and format tables.
| Tags | Description |
| table | define a table. |
| th | define a header cell in an HTML table. |
| tr | define a row in an HTML table. |
| td | define a cell in an HTML table. |
| caption | used to caption a table. |
| colgroup | used in HTML and documents to group multiple columns in tables. |
| col | specify properties for columns inside a tag. |
| thead | Grouping of the header content. |
| tbody | Grouping of the body content. |
| tfoot | Grouping of the footer content. |
Answer:The ng-show and ng-if directives exhibit similar behavior, influencing the performance of web applications developed using Angular.Js. To better understand these terms, let’s explore their distinctions:
| ng-show Directive | ng-if Directive |
| This directive serves the purpose of displaying or hiding HTML elements based on the expression provided within the associated attribute. | This directive is used to conditionally create or remove a portion of the DOM tree based on the specified expression. |
| It facilitates the toggling of rendered data visibility in the application. | It engages in creating or removing DOM elements based on the provided expression’s truthiness. |
| The ng-show directive does not remove or recreate DOM elements; rather, it alters the visibility state of elements based on the condition. | Unlike ng-show, ng-if physically adds or removes elements from the DOM based on the given condition. |
| This directive evaluates the provided condition and controls the visibility of elements accordingly. | The ng-if directive only processes data when the specified condition evaluates as true, optimizing performance by avoiding unnecessary rendering. |
Answer:
The term “React Hooks” refers to a JavaScript-based functional programming feature utilized in React applications to encapsulate the logic of reusable components. By leveraging React Hooks, developers can harness various features of React without the need for class components, thereby promoting a more concise and streamlined coding approach.
Answer:
In React Js, HOC stands for Higher-Order Components. HOC is an advanced technique employed by developers to enhance code reusability by abstracting and encapsulating a component’s functionality. It involves taking an existing base component, processing it with additional logic, and returning an enhanced version of the component.
Answer:
Opting for React Js for front-end development offers numerous advantages, including:
- Superior functionality and faster rendering of web pages.
- Remarkable flexibility and stability, along with seamless testing and development.
- Emphasis on reusable and UI-focused component architecture.
- Trusted by major tech companies and boasts an active and vibrant community.
- Enhanced security due to its unique data abstraction layer, which minimizes code exposure to users.
Answer:
Clustering is a crucial concept in Node.Js aimed at boosting application performance. Since Node.js applications function on a single processor, they cannot inherently leverage multi-core machines. Clustering involves launching multiple Node.js processes simultaneously, resulting in multiple event loop instances. The cluster manager, a parent process, oversees the well-being of individual instances, effectively utilizing machine resources.
Answer:
Middleware in Express.Js refers to a handler function that intercepts and interacts with the request-response cycle of an application. It functions as an intermediary, holding the request and response objects. Middleware executes after the server receives a request but before the controller actions generate a response.
Answer:
Diverse types of middleware in Express.Js include:
- Application-Level Middleware
- Router-Level Middleware
- Error Handling Middleware
- Built-in Middleware
- Third-Party Middleware
Answer:
MongoDB Shards are individual instances within MongoDB that hold subsets of sharded data. They can be employed as replica sets to ensure data redundancy and enhance data availability. A complete set in MongoDB is a composition of multiple shards. The practice of distributing data across multiple host locations is referred to as sharding, accomplished by partitioning data into smaller, manageable units.
Answer:
- Data Definition Language (DDL): DDL commands are responsible for defining and managing the structure of a database schema. They include commands like CREATE (to create objects like tables, indexes, etc.), ALTER (to modify existing objects), and DROP (to delete objects).
- Data Manipulation Language (DML): DML commands are used to interact with data within the database. They include commands like SELECT (to retrieve data), INSERT (to add new records), UPDATE (to modify existing records), and DELETE (to remove records).
- Data Control Language (DCL): DCL commands regulate access control and permissions within the database. Commands like GRANT (to provide specific privileges to users) and REVOKE (to remove privileges) are part of DCL.
- Transaction Control Language (TCL): TCL commands are employed to manage transactions within the database. These include commands like COMMIT (to save changes made during a transaction), ROLLBACK (to undo changes), SAVEPOINT (to set a point for rolling back), and SET TRANSACTION (to configure transaction properties).
Answer:
PostgreSQL offers various data types, including but not limited to:
- Numeric types
- Character types
- Temporal types
- Boolean
- UUID
- Geometric primitives
- Arbitrary precision numeric
- XML
- Arrays, and more.
Answer:
A CSS Preprocessor is a tool that extends the capabilities of standard CSS using its own scripting language. It allows developers to use features like variables, functions, mixins, inheritance, and more, resulting in cleaner and more maintainable stylesheets.
- Sass (Syntactically Awesome Style Sheets): Sass is a popular CSS preprocessor that minimizes repetition in CSS by introducing variables, nesting, mixins, and more. It has two syntaxes: Sass (indented) and SCSS (similar to CSS).
- Less (Leaner Stylesheets): Less also adds advanced features to CSS, enhancing maintainability. It offers features like variables, mixins, and nested rules.
- Stylus:Stylus is known for its concise syntax and flexibility. It supports native CSS, reducing the need for brackets, colons, and semicolons. It also introduces unique features like automatic vendor prefixing.
These preprocessors are used to streamline development, enhance code reusability, maintainability, and allow for more advanced and dynamic styling capabilities.
Answer:
A boilerplate in an HTML document refers to a standard and foundational code structure that provides a starting point for building web pages. This boilerplate typically includes essential elements like the DOCTYPE declaration, `html`, `head`, and `body` tags, charset declaration, and often links to external resources such as CSS files and JavaScript libraries. By using a boilerplate, developers ensure consistent and standardized coding practices across their projects, saving time and effort in setting up the initial structure.
Answer:
The `!DOCTYPE` declaration in an HTML document serves as a declaration that defines the document type and version. It informs the web browser about the type of document being used and its version. The `!DOCTYPE` declaration is essential for accurate rendering and interpretation of the HTML code by the browser.
Answer:
Callback Hell, also known as the Pyramid of Doom, refers to a programming situation in asynchronous JavaScript where multiple nested callback functions create complex and hard-to-maintain code structures. This arises when multiple asynchronous functions are dependent on each other’s outcomes, leading to deeply nested callback functions. The result is code that is difficult to read, comprehend, and debug. Callback Hell can be mitigated by using techniques like Promises or async/await.
Answer:
Continuous Integration (CI) is a DevOps practice that involves automating the integration of code changes into a shared repository multiple times a day. It includes automated tests and builds to validate the correctness of new code changes before integrating them. CI ensures that new code additions don’t break existing functionality and facilitates early detection of bugs, leading to faster and more reliable software development.
Answer:
Advantages of “use strict”:
- Detects common coding mistakes by throwing errors.
- Optimizes code that might be tough for JavaScript engines to optimize without strict mode.
- Prevents the use of poorly thought-out or confusing features.
- Provides a more secure and accurate coding environment.
Drawbacks of “use strict”:
- Many commonly used functions are unavailable.
- Access to `function.caller` and `function.arguments` is restricted.
- Compatibility issues with older browsers.
- Concatenating scripts written with different strict modes may cause problems.