Coding & Skills
204 articles in this topic
JWT Authentication in Node.js and Express: Access Tokens, Refresh Tokens, and the Security Pitfalls That Leak Accounts
Trace a complete Express login, protected request, expiry, and refresh cycle. Then fix the token mistakes that make an apparently working system unsafe.
Java Coding Interview Questions: Programs Asked in Service-Company Drives
Prepare the short Java programs that recur in fresher drives. Learn the core string, array, number and collections patterns, then trace an O(n) Two-Sum solution.
OOP in Python: Classes, Inheritance, the MRO Diamond and Dunder Methods for Interviews
Work through Python's MRO diamond and the __eq__ plus __hash__ rule. These two examples explain many of the OOP output questions asked in interviews.
Python for GATE DA: Programming and Data Structures, the Output Questions to Master
Build the Python mental model that GATE DA output and complexity questions demand, with a complete aliasing trace, a structure-cost table and safe rules for common traps.
Language Design in Programming Languages: Syntax, Types, Scope and a Worked Evaluation
Trace one expression from source text to a value, then compare the design rules that make scope, typing, evaluation and mutation behave differently.
Function Overloading and Default Arguments in C++: Rules and Runnable Examples
Learn why overloading and default arguments are different C++ mechanisms. Compile one invoice program, trace every call, and repair ambiguous code.
Genetic Algorithms in AI: Complete Guide with a Worked One-Generation Example
Learn the complete genetic algorithm loop, then calculate selection, crossover, mutation, and fitness improvement by hand on a four-chromosome population.
Command Line Arguments in C: argc and argv Tutorial with Runnable Examples
Learn how argc and argv carry command line input into a C program, then practise argument tracing, numeric conversion, validation, and common fixes.
HTML Forms Explained: Input Types, Validation Attributes, and the MCQs That Test Them
Build one registration form, trace its submitted data, and learn the input and validation details that HTML MCQs and frontend interviews repeatedly test.
OOPs Concepts in Java: Inheritance, Polymorphism, Abstraction and Encapsulation with Worked Interview Questions
Turn the four OOP pillars into predictable Java behaviour. Trace superclass references, subclass objects, overridden methods, hidden fields and common follow-ups.
String Problems in Python for Coding Rounds: Palindromes, Anagrams and Compression Solved
Python turns common string problems into one-liners, but interviewers usually remove that shortcut next. Learn the Pythonic and manual solutions for three recurring patterns.
HashMap Internal Working in Java: Hashing, Buckets, Treeification and the Interview Answer
Build the interview answer in four layers: index calculation, collision handling, resizing and treeification. Then test it against a mutable-key failure.