HashMap
A HashMap is a data structure that stores key-value pairs using hashing for fast access, insertion and deletion. Keys are unique and each maps to exactly one value. It offers average O(1) time complexity for basic operations and is widely used for efficient lookups, caching and data mapping in applications.
Top HashMap Articles
Amazon Transaction Logs
Amazon Transaction Logs (example question), Amazon Transaction Logs Interview question
Popular Topics
DatabaseChallangeMySQLgit branchInterviewLanguage-ConceptsJavaControl Flow Git CommitTwo Pointes
A database is an organized collection of data. It is the collection of schemas, tables, queries, reports, views, and other objects. The data are typically organized to model aspects of reality in a way that supports processes requiring information. Use this tag if you have questions about designing a database.
A challenge is a task, problem or situation that tests a person’s skills, knowledge or determination. Challenges encourage growth by pushing individuals beyond their comfort zones and inspiring creative problem-solving. In learning, technology and work environments, challenges help improve abilities, build confidence and lead to meaningful achievements through consistent effort and resilience.
MySQL is an open-source relational database management system widely used for storing and managing structured data. It supports SQL for querying, updating and controlling data efficiently. Known for reliability, speed and scalability, MySQL powers web applications, enterprise systems and cloud platforms. It is commonly used with PHP, Java, Python and modern application stacks like LAMP and MERN.
git branch is a command used to manage branches within a Git repository. It allows developers to create, list, rename and delete branches. Branches enable parallel development, feature isolation and safe experimentation without affecting the main codebase. Using git branch helps teams organize work efficiently and maintain clean, structured workflows during development.
A structured conversation where one participant asks questions and the other provides answers of those questions.
This tag is used to understand a basic part of the language.
Java is a high-level object-oriented programming language. it's firstly released by Sun Microsystems in 1995. Use this tag when you're having queries using or understanding the language. This tag is also applicable to Java libraries and frameworks.
A git commit is a command used to save changes to the local repository, creating a snapshot of the project at a specific point in time. Each commit includes a unique ID, message and details of modified files. Commits help track progress, document work and enable reverting or reviewing changes, forming the foundation of version control in Git.
The two-pointer technique is an efficient algorithmic approach that uses two indexes to traverse data structures like arrays or strings. The pointers move toward each other, away from each other or in the same direction to solve problems involving searching, pair finding or window management. It reduces complexity, often turning O(n²) solutions into O(n), making it ideal for optimized problem-solving.
Popular Articles
how to install docker on amazon ec2 instance. docker installation command on linux machine, docker commands, Commonly Used Docker Commands on EC2
Top High-Level Design(HLD) Interview Questions and answers, HLD QnA, HLD interview preparation
Maximum Product Subarray, Find Maximum Product Subarray in an Array, Given an integer array arr, find a subarray that has the largest product,
Learn how to create a primary key in SQL using syntax and examples. Ensure unique records, improve query performance and build table relationships.
Mastering the Singleton Design Pattern in C#, Singleton Design Pattern in Depth: Structure, Use Cases and Best Practices, in depth design pattern, LLD , low level design
A Structured Approach to Cracking Technical Interviews. how to prepare for Technical Interviews? Technical Interviews preparation guideline
Length of the Longest Substring Without Repeating Characters | Given a string str find the length of the longest substring without repeating characters | find the length of the longest substring without repeating characters in a given string |
List Handling in Java vs C# vs C++ A Deep Comparison, This comparison provides a full view java , c# and c++ List like data structures
namespace in c# | namspace concept in c# | c# namespace | c sharp namespace | what is namesapce and it's use cases | why should we use namespace
Most Popular Tools
Explore our top online tools including a blank page for notes, a QR code generator, word counter and collaborative editor. These free, easy-to-use utilities help you write, analyze, share and organize content faster. Perfect for developers, creators and students to streamline everyday digital tasks efficiently.
Blank Page
Create a blank canvas for your ideas, notes or sketches. Use this tool for rough work and jotting down your thoughts
QR Code Generator
A QR Code Generator is a tool that instantly converts text, URLs or other data into a scannable QR code. Users can create custom QR codes for websites, contact info or messages. It's commonly used for quick access, sharing and printing without needing a backend or complex setup.
Word Counter
Perform various string operations like counting characters, words or letters.
Collaborative Editor
Collab Editor is a powerful, free-to-use online platform that lets you collaborate in real-time. Whether you re working on documents, brainstorming idea, or discussing projects etc