Important Notice— Our url is 
Full Stack Interview Questions and Answers- Part 8
Are you ready to take your full stack development career to the next level? A strong interview performance can make all the difference. To help you succeed, we’ve created a guide filled with full stack interview questions and answers. These questions are perfect for developers who want to brush up on key concepts before facing technical interviews.
Full stack roles often require knowledge of both client-side and server-side development, which means you’ll be tested on everything from UI design to back-end logic. In this blog, we cover questions on JavaScript, React, Node.js, databases, and web development tools. Whether you’re a beginner or already working in tech, these questions will help you improve your understanding and get job-ready.
Answer:
A Callback function in JavaScript is a function that is passed as an argument to another function. It is executed after the completion of the function it was passed to, regardless of the order in which functions are defined. Callbacks enable asynchronous programming and help manage operations that take time to complete.
Answer:
- MEAN stack – MongoDB, Express.js, Angular.js, Node.js
- MERN stack – MongoDB, Express.js, React.js, Node.js
Alternatives:
- MEVN stack: MongoDB, Express.js, Vue.js, Node.js
- LAMP stack: Linux, Apache, MySQL, PHP
- PERN stack: PostgreSQL, Express.js, React.js, Node.js
Answer:
Scope in AngularJS refers to the context where variables are accessible. There are two types of scope:
- $scope: A scope is an object that connects the controller and the view, facilitating communication and data binding between them.
- $rootScope: The top-level scope in AngularJS, shared across all components. It acts as a global variable accessible to all scopes.
Answer:
Directives in AngularJS are classes that extend the functionality of HTML elements or create new behavior in templates. They manipulate the DOM by adding, modifying, or removing elements, providing control over the user interface. There are three types: Component, Attribute, and Structural directives.
Answer:
Node.js is considered a single-threaded framework because it uses an event loop architecture, allowing a single thread to efficiently handle asynchronous operations. Although it uses a single thread for event handling, it can effectively manage multiple concurrent connections and tasks due to its non-blocking I/O operations.
Node.js features:
- Open-source framework
- Asynchronous programming model
- NPM for package management
- High performance and scalability
- Single-threaded event loop architecture
Answer:
NPM (Node Package Manager) is a registry and command-line tool for managing Node.js packages and dependencies. It allows developers to easily share, install, and manage libraries, tools, and modules within Node.js applications. NPM consists of a website for package discovery, a command-line interface for interacting with the registry, and the registry itself.
NPM is used with Node.js to streamline the development process by providing a convenient way to install third-party packages, manage dependencies, and ensure consistent development environments across different machines.
Answer:
CORS (Cross-Origin Resource Sharing) is a browser mechanism that enables web pages in one domain to access resources hosted on another domain. It relaxes the Same-Origin Policy, allowing cross-domain requests. CORS prevents security vulnerabilities while allowing controlled sharing of resources.
To include CORS in Express.js, you can use the `cors` middleware. First, install the `cors` package using npm (`npm install cors`). Then, require and use the middleware in your Express application to handle CORS-related headers and options.
Answer:
Replication in MongoDB is the process of synchronizing data across multiple servers to ensure redundancy and high availability. It involves maintaining multiple copies of the data on separate database servers. Replication provides data recovery options in case of hardware failures, service interruptions, or other issues. It enhances data availability, fault tolerance, and read scalability.
Answer:
You can create a new database in PostgreSQL using either of these two methods:
- Using pgAdmin: Access the pgAdmin GUI and use its interface to create a new database by specifying the necessary details.
- Using SQL Shell: Launch the SQL Shell (psql) and execute SQL commands to create a new database using the `CREATE DATABASE` statement.
Answer:
| WHERE Clause | HAVING Clause |
| Used to filter records from a table based on a specified condition. | Used to filter records from a group based on a specified condition. |
| Can be used without the GROUP BY clause. | Requires the use of the GROUP BY clause. |
| Operates on individual rows of data (row-major). | Operates on groups of data (column-major). |
| Supports statements like SELECT, UPDATE, and DELETE. | Accommodates aggregate functions. |
Answer:
An RDBMS, or Relational Database Management System, is a specialized type of DBMS (Database Management System) used for organizing and managing data in a structured manner. It stores data in tables composed of rows and columns, where each row represents a record and each column represents a data attribute. RDBMSs establish relationships between tables through keys, enabling efficient data retrieval and manipulation. They provide features to ensure data accuracy, integrity, and security. Users can create, modify, and query relational databases using an RDBMS.
A DBMS, on the other hand, is a broader term that encompasses various systems for creating and managing databases. While an RDBMS focuses specifically on managing relational databases, a DBMS can handle different types of databases, including hierarchical, network, and object-oriented databases. Unlike RDBMS, a generic DBMS may not enforce the same level of data consistency and relationships as an RDBMS does.
Answer:
| RDBMS | DBMS |
| Stores data in tabular form, using tables with rows and columns. | Stores data in various formats, like files or hierarchical structures. |
| Data in RDBMS is indexed for efficient retrieval, permitting an optimized querying. | Indexing may not be as prevalent or efficient as due to the varied storage methods. |
| Due to the structured nature of tabular data multiple data elements can be accessed concurrently. | Only individual data elements can be accessed at a time, making complex queries complex. |
| Follows the concept of normalization, ensuring data integrity by minimizing redundancy and organizing data into related tables. | The concept of normalization is absent and data relationships are unstructured. |
| Supports distributed databases, handling large amounts of data across locations. | Used for smaller data quantities and may lack robust support for distributed systems. |
Answer:
Cluster Indexes: In PostgreSQL, a Cluster Index is utilized to arrange rows within a table based on their key values. Only one clustered index can be present in a table, and it determines the physical order of data storage. Typically, the primary key is used to create a clustered index, which organizes data based on the primary key column’s values.
Non-Cluster Indexes: Non-cluster indexes in PostgreSQL store index data separately from the actual data. These indexes use pointers to indicate the location of data. Also known as secondary indexes, multiple non-clustered indexes can exist on a single table. Unlike cluster indexes, non-cluster indexes do not directly affect the physical storage order of data.
Answer:
The difference between the DROP command and the TRUNCATE command in SQL are as follows-
| DROP Command | TRUNCATE Command |
| Removes the whole table from the database. | Deletes all the rows present in the table. |
| Deletes the whole structure of the table in the database as well as the memory allocated. | Does not delete the whole structure of the table from the database and even don’t free the allocated memory. |
| The action cannot be undone once the DROP command is applied. | It can be undone. |
| The execution speed is slower compared to the TRUNCATE command. | The execution speed is faster compared to the DROP command. |
| The view table doesn’t exist in the DROP command. | The view table exists in the TRUNCATE command. |
| Syntax –DROP TABLE Intellipaat; | Syntax –TRUNCATE TABLE Intellipaat; |
Answer:
In Node.js, Buffers refer to fixed-size blocks of memory used to store and manipulate raw binary data. The size of a buffer is determined when it’s created and cannot be changed afterward. Buffers are suitable for handling binary data, such as file contents or network data. While similar to arrays, buffers are specialized for working with binary data and do not possess the dynamic resizing capability of arrays. Each integer in a buffer represents a single byte, and you can use console.log() to print the Buffer instance.
Answer:
Streams in Node.js are an abstract interface designed to handle continuous streaming of data during processing. Node.js provides an API called stream to implement this interface. There are various types of stream objects in Node.js:
- Readable Stream: Generates a stream of data for reading.
- Writable Stream: Generates a stream of data for writing.
- Duplex Stream: Combines both readable and writable functionalities.
- Transform Stream: Alters data while it’s being read or written.
Answer:
In Express.js, Scaffolding refers to the process of creating a basic framework or structure for a web application. It involves setting up essential files, directories, and initial configurations. Scaffolding can also include creating routes, adding middleware, and preparing the application’s foundation for development. Scaffolding aids developers in kickstarting the application development process by providing a starting point.
Answer:
Yes, the Model-View-Controller (MVC) architectural pattern, which is commonly used in Express.js and other web frameworks, supports scaffolding. MVC promotes the separation of concerns in an application. Scaffolding in the context of MVC involves generating the basic components of the application’s structure: Models, Views, and Controllers. This accelerates the development process by providing a structured foundation, allowing developers to focus on implementing the specific functionalities of their application.
| Node.Js | Django |
| Node.Js is a type of open-source framework centered on JavaScript useful for developing web applications. | Django is a type of open-source framework on Python useful for developing web applications. |
| The framework Node.Js is developed using C, CPP, and JavaScript programming languages. | The framework Django is created using Python programming. |
| Applications crafted using Node.Js are more scalable | Applications crafted using Django are less scalable |
| Node.Js follows the event-driven programming concept. | Django follows the Model View Template architecture concept at the time of development. |
Answer:
Interpolation in Angular.Js serves as a means to convey data of TypeScript code to an HTML view. Through this mechanism, expressions can be embedded within text to assess the value of the expression. Angular.Js employs interpolation for one-way data binding, facilitating the connection of data with application logic.
Interpolation syntax: {{expression}}
Angular.Js augments HTML functionality by employing directives, enabling dynamic interaction between HTML data and the Angular.Js application. There are three fundamental ways in which Angular.Js extends HTML:
- ng-app: This directive defines the Angular.Js application being developed.
- ng-model: Employed to bind HTML control values.
- ng-bind: Utilized to connect the HTML view with application data, ensuring dynamic updates.