Geekyants Interview Questions

Intermediate Level Geekyants Interview Questions 

11. Explain the concept of responsive design.

Responsive design is an approach to web design that aims to create websites that adapt and provide an optimal viewing experience across a wide range of devices, including desktops, tablets, and mobile phones.

Key principles of responsive design:

• Flexible layouts that adjust to different screen sizes using relative units and media queries.
   
• Fluid images and media that scale proportionally to fit the available space.
   
• Media queries to apply different styles based on the device's screen size and resolution.
   
• Prioritized content and navigation for smaller screens, ensuring usability on mobile devices.

12. What is a CSS preprocessor?

A CSS preprocessor is a tool that extends the capabilities of traditional CSS by introducing additional features and syntax. It allows developers to write more maintainable, reusable, and efficient CSS code.

Key features of CSS preprocessors:

• Variables for storing and reusing values throughout the stylesheet.
   
• Nesting selectors to create more readable and hierarchical code structure.
   
• Mixins for encapsulating and reusing sets of CSS properties.
   
• Functions and operators for performing calculations and manipulating values.
   
• Imports and partials for modularizing and organizing CSS code into smaller, manageable files.

13. Explain the concept of promises in JavaScript.

Promises in JavaScript provide a way to handle asynchronous operations and manage their results or errors. They represent a value that may not be available immediately but will be resolved at some point in the future.

Key points about promises:

• It was created using the Promise constructor, which takes a callback function (executor) as an argument.
   
• The executor function receives two arguments: resolve and reject, used to control the promise's outcome.
   
• Promises have three states: pending (initial state), fulfilled (operation completed successfully), or rejected (operation encountered an error).
   
• It can be chained using .then() and .catch() methods to handle the fulfilled and rejected states, respectively.
   
• Enable cleaner and more readable asynchronous code compared to nested callbacks.

14. Describe how inter-process communication works.

Inter-process communication (IPC) refers to the mechanisms and techniques used by processes to exchange data and coordinate their activities.

Key points about IPC:

Enables processes to share information, synchronize actions, and collaborate on tasks.

Can be achieved through various methods, such as:

• Shared memory: Processes access a common region of memory to read and write data.
   
• Message passing: Processes send and receive messages through communication channels (e.g., pipes, sockets).
   
• Signals: Processes send and receive system-level notifications to convey information or trigger actions.

15. What is the purpose of a firewall?

A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

Key purposes of a firewall:

• Establishes a barrier between a trusted internal network and an untrusted external network (e.g., the internet).
   
• Filters and restricts network traffic based on specified rules and policies.
   
• Prevents unauthorized access, malicious attacks, and data breaches from external sources.
   
• Can be hardware-based (separate device) or software-based (running on a server or individual computer).
   
• Helps enforce network security policies and protect the confidentiality, integrity, and availability of network resources.

16. Explain the concept of closures in JavaScript.

Closures in JavaScript are a fundamental concept that allows a function to access variables from its outer (enclosing) lexical scope even after the outer function has finished executing.

Key points about closures:

• A closure is created when a function is defined within another function, allowing the inner function to access variables and parameters of the outer function.
   
• The inner function retains access to the outer function's scope, even after the outer function has returned.
   
• Closures provide a way to create private variables and encapsulate data, as the enclosed variables are not accessible from outside the closure.
   
• Closures are commonly used for data privacy, event handlers, and creating function factories.

17. Explain the difference between a process and a thread.

18. Describe how you would handle authentication in a web application.

Authentication is the process of verifying the identity of users and granting access to protected resources based on their credentials.

• User Registration: Provide a registration form for users to create an account, validate inputs, and securely store user credentials (e.g., hashed passwords) in a database.
   
• User Login: Present a login form for users to enter their credentials, validate the provided credentials against the stored user information, and establish an authenticated session upon successful login.
   
• Session Management: Store the session or token securely on the server-side, include it in subsequent requests to identify the authenticated user, and implement session expiration and logout mechanisms.
   
• Access Control: Define user roles and permissions, protect sensitive routes and resources by verifying authentication and authorization, and implement server-side checks to ensure only authorized users can access protected resources.
   
• Secure Communication: Use HTTPS to encrypt data transmission, implement secure cookie settings, and follow security best practices to protect sensitive information.
   
• Password Security: Encourage strong passwords, implement password complexity requirements, and use secure password hashing algorithms to store passwords in the database.

19. How does DHCP work?

DHCP (Dynamic Host Configuration Protocol) is a network protocol that automatically assigns IP addresses and other network configuration parameters to devices on a network.

Let’s see how it works : 

• DHCP Discovery: The device broadcasts a DHCP discovery message to locate available DHCP servers.
   
• DHCP Offer: DHCP servers respond with a DHCP offer message containing an available IP address and other configuration parameters.
   
• DHCP Request: The device selects an offer and sends a DHCP request message to the chosen server, requesting the offered IP address.
   
• DHCP Acknowledgement: The server sends a DHCP acknowledgment message to the device, confirming the IP address assignment and lease duration.

20. Explain how a scheduler works in an operating system.

A scheduler in an operating system is responsible for determining which processes or threads should be executed by the CPU at any given time.

Let’s see how it works : 

• Process States: The scheduler keeps track of the state of each process (running, ready, waiting, or terminated) and manages their transitions.
   
• Scheduling Algorithms: The scheduler uses algorithms like FCFS, SJF, Priority, or Round Robin to determine the order and priority of process execution.
   
• Context Switching: The scheduler saves the current state of a process and loads the state of the next process to be executed.
   
• Process Creation and Termination: The scheduler handles the creation and initialization of new processes and cleans up resources when a process completes or terminates.

Advanced Level Geekyants Interview Questions 

21. Explain the concept of network topology.

Network topology refers to the physical or logical layout of a network, describing how devices are connected and how data flows between them.

• Physical Topology: Describes the physical arrangement of devices, cables, and network components (e.g., bus, star, ring, mesh).
   
• Logical Topology: Describes how data flows between devices, regardless of their physical arrangement (e.g., Ethernet, Token Ring).
   
• Hybrid Topology: Combines elements of different physical and logical topologies for flexibility and scalability.

22. Write a JavaScript function to perform a deep copy of an object.

function deepCopy(obj) {
  if (typeof obj !== 'object' || obj === null) {
    return obj;
  }
  let copy = Array.isArray(obj) ? [] : {};
  for (let key in obj) {
    if (obj.hasOwnProperty(key)) {
      copy[key] = deepCopy(obj[key]);
    }
  }
  return copy;
}

The deepCopy function recursively copies an object and its nested objects, creating a new object with the same structure and values.

23. Describe the role of the kernel in an operating system.

The kernel is the core component of an operating system that acts as an interface between the hardware and the software.

Kernel plays a crucial role in OS like : 

• Resource Management: The kernel manages system resources (CPU, memory, I/O devices) and allocates them to processes.
   
• Process Management: The kernel creates, schedules, and terminates processes, and provides inter-process communication mechanisms.
   
• Memory Management: The kernel manages memory allocation, protection, and virtual memory mechanisms.
   
• Device Drivers: The kernel includes drivers that facilitate communication between the operating system and hardware devices.
   
• System Calls: The kernel provides system calls that allow user-level processes to request services from the operating system.

24. What is the difference between paging and segmentation?

25. Write a function to perform binary search on a sorted array.

def binary_search(arr, target):
    low = 0
    high = len(arr) - 1
  while low <= high:
        mid = (low + high) // 2
        if arr[mid] == target:
            return mid
        elif arr[mid] < target:
            low = mid + 1
        else:
            high = mid - 1
    return -1

26. How does SSL/TLS encryption work?

SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are cryptographic protocols that provide secure communication over a network.

It works in the below mentioned manner : 

• Handshake: The client and server establish a secure connection by exchanging digital certificates and generating a session key.
   
• Key Exchange: The client encrypts the session key using the server's public key, and the server decrypts it using its private key.
   
• Data Encryption: The client and server use the shared session key to encrypt and decrypt the data exchanged between them.
   
• Message Authentication: SSL/TLS uses hash functions to ensure the integrity of the transmitted data and detect tampering.

27. Explain the difference between IPv4 and IPv6.

28. How do you perform a breadth-first search (BFS) on a graph? 

Steps to perform BFS on a graph:

1. Choose a starting node and add it to a queue.
    
2. Mark the starting node as visited.
    
3. While the queue is not empty, do the following:

• Dequeue a node from the queue.
   
• Process the dequeued node (e.g., print its value).
   
• Enqueue all the unvisited neighbors of the dequeued node.
   
• Mark the visited neighbors as visited.
   

Repeat step 3 until the queue is empty.

Example of BFS in python : 

from collections import deque
def bfs(graph, start):
    visited = set()
    queue = deque([start])
visited.add(start)
while queue:
    node = queue.popleft()
    print(node)
    for neighbor in graph[node]:
        if neighbor not in visited:
            queue.append(neighbor)
            visited.add(neighbor)

29. What is a deadlock in databases, and how can it be prevented?

A deadlock in databases occurs when two or more transactions are waiting for each other to release locks on resources, resulting in a circular dependency.

We can prevent deadlock in below mentioned ways : 

1. Timeout mechanism: Set a timeout period for transactions to acquire locks, and abort if exceeded.
    
2. Resource ordering: Define a specific order in which resources must be acquired to avoid circular wait.
    
3. Deadlock detection and resolution: Periodically check for deadlocks and resolve by aborting one or more transactions.
    
4. Two-phase locking (2PL): Transactions acquire all necessary locks before executing and release them only after completing.
    
5. Optimistic concurrency control: Allow transactions to execute without locks and check for conflicts at commit time.

30. Write a program to check if the strings are rotations of each other or not

def are_rotations(str1, str2):
    if len(str1) != len(str2):
        return False
    concatenated = str1 + str1
    if str2 in concatenated:
        return True
    else:
        return False
# Example usage
string1 = "waterbottle"
string2 = "erbottlewat"
result = are_rotations(string1, string2)
print(result) 

Output: 

True

The program checks if two strings are rotations of each other by concatenating the first string with itself and checking if the second string is a substring of the concatenated string. If the lengths of the strings are different, they cannot be rotations of each other.

Conclusion

We hope you have gained some insights on Geekyants Interview Questions through this article. We hope this will help you excel in your interviews for Geekyants. 

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