Developer topics that might interest you!

This lesson introduces the basic lambda expression structure with tips to write efficient code.

Learn why Kafka events are immutable facts, not commands, and how that decouples services. Modeled on the passport lifecycle with Java 21 records.

Learn the single data structure — the append-only, partitioned commit log — that makes Apache Kafka fundamentally different from a queue or a database.

Apache Kafka is a distributed event streaming platform built for high-throughput, fault-tolerant, real-time data pipelines. In 60 seconds, learn the core mental model every Java developer needs before writing a single line of Kafka code.

Learn why Apache Kafka was built to solve the N×N integration mess, and the problem Kafka was built to solve. Meet the Passport Lifecycle project we'll build all program long.

Learn why Apache Kafka was built to solve the N×N integration mess, and the problem Kafka was built to solve. Meet the Passport Lifecycle project we'll build all program long.

This lesson introduces the basic lambda expression structure with tips to write efficient code.

This is an introductory lesson on lambda expressions. You will learn about the lambda operator, expression, syntaxes and more!

This is an exercise problem for your practice. Try to come up with an approach and solve it by yourself. Good Luck!

This is an exercise problem for your practice. Try to come up with an approach and solve it by yourself. Good Luck!

Unary and Binary operators are the other two functional interfaces that most developers are interested in.

This lesson talks about the third functional interface, which is the BiFunction.

This lesson talks about the third functional interface, which is the Predicate.

This lesson talks about the third functional interface, which is the Function.

This lesson talks about the second functional interface, which is the Supplier.

This lesson talks about the first functional interface, which is the Consumer.

This lesson details about the various functional interfaces that fall under major 4 categories.

This is the introductory lesson on functional interfaces. Introduced in Java SE 8, these are powerful and most useful as either lambdas or method reference can use it.

In this lesson, you will learn how immutability is achieved through functional programming.

In this lesson, you will learn how immutability is achieved through functional programming.

This lesson details pure and impure functions with various examples for understanding.

Functional programming solves almost all of the business use cases OOP solves. In fact, functional programming reduces bugs due to its immutability in nature.

In this lesson, you will learn about functional programming and the fundamental differences between object-oriented and functional programming.

In this lesson, you will learn declarative programming and the steps to achieve it. You will also be introduced to some real-world use cases for easy understanding.

In this lesson, you will learn imperative programming and the steps to achieve it. You will also be introduced to some real-world use cases for easy understanding.

In this lesson, you will learn various programming paradigms in computer science.

Functional programming is a paradigm that treats computation as the evaluation of functions, avoiding shared mutable state and side effects. It is far older than Java — Lisp introduced these ideas in 1958 — but Java only gained first-class support for it in Java SE 8 (March 2014), when lambda expressions,

This course has taught you how to re-write arithmetic operators like +, -, /, * into left, right shift, and other bit-level operations. I hope the knowledge you gain in this course will be useful in solving Leetcode, Hackerrank, HackerEarth, Codeforces, Codechef, and other online coding challenges. It will also help you

Real-time data isn't "we'll know eventually" — it's knowing the instant something happens and acting on it. This lesson breaks down what real-time actually means, why Kafka exists, and how one event reaches many systems at once, in plain English.

In the kth bit set/unset problem, we first write the algorithm, then some pseudocode, and then implement the solution. In this lesson, we try to solve this algorithm using the left shift operator. Try solving it on your own. Solution review Imagine we check the right-most significant bit

This problem is similar to the last lesson we discussed. If you need a clue, return to the previous lesson to further your understanding. Introduction In this question, we need to find the first set-bit position from the right. Problem statement Given an input number, find the first set-

In the kth bit set/unset problem, we need to write a program that checks whether the kth bit of a number is 1 or 0. In this lesson, we try to find a bit in the binary representation of a number at the kth position and check if it

In the kth bit set/unset problem, we first write the algorithm, then some pseudocode, and then implement the solution. In this lesson, we try to solve this algorithm using the left shift operator. Try solving it on your own. Solution review Imagine we check the right-most significant bit

This problem is similar to the last lesson we discussed. If you need a clue, return to the previous lesson to further your understanding. Introduction In this question, we need to find the first set-bit position from the right. Problem statement Given an input number, find the first set-

Learn how Java strings work as keys in HashMap, TreeMap, and HashSet collections. Master string comparison, hash codes, and avoid common pitfalls like case sensitivity and performance issues with long strings in data structures.

Java StringBuffer vs StringBuilder: Thread Safety Guide. Learn when to use synchronized StringBuffer for multi-threaded apps vs faster StringBuilder for single-threaded performance. Complete comparison with examples and best practices for optimal string manipulation.

Learn Java StringBuilder vs String concatenation performance! Discover why StringBuilder outperforms + operator in loops, avoid costly intermediate objects, and optimize Java string operations. Includes timing benchmarks & code examples. Master efficient Java string manipulation techniques.

Learn Java String vs StringBuilder vs StringBuffer differences. Master efficient string manipulation with mutable StringBuilder for performance-critical apps. Covers append(), insert(), delete() methods, thread-safety, and when to use each class for optimal Java programming.

Learn Java String Immutability: Why Java strings are immutable, benefits of thread safety & string pooling, memory impact, performance considerations. Master string consistency, hashcode caching & when to use StringBuilder for efficient Java programming.

Learn Java number formatting with NumberFormat and DecimalFormat classes. Master currency formatting, decimal places, thousands separators, and locale-specific displays. Complete tutorial with examples for professional Java string manipulation and number display.

Learn Java string parsing to primitive types with Integer.parseInt(), Double.parseDouble(), Float.parseFloat() methods. Convert string to int, double, boolean safely using try-catch blocks to handle NumberFormatException. Master Java number conversion techniques.

Learn Java String formatting with String.format() method using %s, %d, %f placeholders. Master format specifiers for strings, integers, floats with decimal control, padding, alignment & leading zeros. Complete tutorial with examples for clean, professional Java output.

Learn essential Java string methods: trim() & strip() for whitespace removal, replace() & replaceAll() for substring replacement, split() to create arrays, & String.join() to recombine. Master Java string manipulation with practical examples.

Learn Java string searching with indexOf() and lastIndexOf() methods. Master finding characters, substrings, and pattern matching using regular expressions. Complete guide to Java string indexing and search techniques with examples.

Learn Java string iteration using for loops and for-each loops. Master charAt() method, toCharArray() conversion, and character array manipulation. Complete guide to iterating through string characters in Java with examples.

Learn Java substring() method to extract parts of strings using startIndex & endIndex. Master string manipulation, handle edge cases like IndexOutOfBounds, and optimize performance. Complete tutorial with examples for Java developers.

Learn Java string concatenation with + operator, concat() method & StringBuilder. Master performance optimization, null handling, and efficient string joining techniques. Complete guide to Java string concatenation with examples and best practices.

Learn Java string comparison methods: equals() vs == operator, compareTo() for sorting, and Objects.equals() for null-safe comparisons. Master string equality checks, avoid NullPointerException, and handle null strings in Java programming.

Learn essential Java String methods: length(), charAt(), equals(), substring(), indexOf(), concat(), and case conversion. Master string manipulation techniques with practical examples for effective Java programming and text processing.

Learn Java strings memory management: heap vs stack allocation, String Pool optimization, and JVM performance. Master string interning, garbage collection, and memory-efficient coding techniques for faster Java applications with reduced memory overhead.

Learn Java String Pool: memory optimization technique where JVM stores string literals in heap memory for efficient reuse. Discover how string pool works, literal vs new keyword differences, performance benefits & memory management from Java 7 onward.

Learn how to create strings in Java using string literals and String constructor methods. Master Java string objects, string pool concepts, and string immutability. Essential Java programming tutorial for beginners and developers.

Learn Java String fundamentals: immutable objects for textual data manipulation. Master String class methods like length(), substring(), charAt() & equals(). Understand object vs primitive differences, memory allocation & thread-safe string operations in Java programming.

Prepare for Maven interviews with 10 common questions and scenario-based answers. Learn about POM, lifecycles, dependencies, plugins, multi-module projects, and best practices for Java developers.

Discover the best practices for Apache Maven: update dependencies regularly, use <dependencyManagement> for version consistency, and minimize snapshot usage in production for stable builds.

Learn how to integrate Maven with CI/CD pipelines using Jenkins and GitHub Actions. Understand skipping tests with -DskipTests and deploying Maven artifacts to Nexus or Artifactory.

Learn Maven multi-module projects with examples. Understand parent POM vs child modules, aggregator vs inheritance, and see a complete multi-module setup for Java applications.

Learn how to use Maven profiles for environment-specific builds. Activate profiles by command-line, property, or OS, and see a practical dev vs prod build example.

Learn how to use Maven plugins like the Compiler Plugin, Surefire Plugin, and Shade Plugin. Configure Maven to compile code, run tests, and create fat JARs in Java projects.

Learn how to handle dependency conflicts in Maven. Use <dependencyManagement> for version consistency, override transitive dependencies, and analyze conflicts with mvn dependency:analyze.

Learn how to manage dependencies in Maven. Understand how to add dependencies in pom.xml, explore dependency scopes (compile, provided, runtime, test), and see how Maven resolves transitive dependencies.

Apache Maven is one of the most popular build automation and dependency management tools in the Java ecosystem. While Maven offers a wide range of commands, a handful of them are used daily by Java developers when building, testing, and managing projects. In this lesson, we’ll cover the most

When working with Apache Maven, every command you execute follows a predefined sequence of steps known as the build lifecycle. Understanding this lifecycle is essential for any Java developer who wants to build, test, and deploy applications efficiently. In this guide, we’ll explore: * Maven’s three standard lifecycles * The

Generate all possible subsets using bit manipulation: left shift operators, binary representation patterns. Master powerset algorithms for coding interviews. Asked by Apple, Microsoft, Amazon, Facebook with multi-language solutions.

Introduction Now that you understand Maven’s installation and project structure, it’s time to create your first Maven project. In this lesson, you’ll learn how to: * Create a Maven project using archetypes * Use the mvn archetype:generate command * Open your Maven project in IntelliJ IDEA or Eclipse By

Learn Maven's standard project structure and directory layout for Java development. Master src/main/java, src/test/java, resources folders, and target build outputs. Follow Maven conventions for better IDE compatibility, team collaboration, and automated builds.

Master Maven pom.xml: Learn GAV coordinates, dependencies, plugins, and build configuration. Complete guide to Project Object Model structure for Java developers. Essential Maven tutorial.

Learn how to install Apache Maven on Windows, macOS & Linux. Step-by-step guide covers downloading, setting JAVA_HOME/MAVEN_HOME environment variables & verifying installation with mvn -v command.

The logical right shift means shifting the bits to the right, and MSB(most significant bit) becomes 0. The arithmetic right shift means shifting the bits to the right, and MSB is the same as in the original number.

The left-shift operator causes the bits in shift-expression to be shifted to the left by the number of positions specified by additive-expression. The bit positions that have been vacated by the shift operation are zero-filled.

A bit shift is a Bitwise operation where the order of a series of bits is moved, either to the left or right, to efficiently perform a mathematical operation.

We solved the problem using lookup (hashtable), using the mathematical formula. Let's solve this more efficiently using bit-level operations with XOR and then optimize the solution.

In this article, we'll learn various ways to find the missing number in an array. We use a memoization approach, a mathematical approach, and the most optimized way using the XOR operator.

Single Number coding question, can be easily solved with XOR bitwise technique with linear time complexity.

In this lesson, every element appears twice except one element. We solve this using naive, and then we move to solve it more optimally using XOR operator.

Hamming distance talks about two integers where the bit positions where the corresponding bits are different.

In this question, input two numbers and detect if they have opposite signs. We solve using bitwise XOR operator

In this coding question, we find the odd-appearing element using bitwise xor. This algorithm is simple yet powerful.

In the kth bit set/unset problem, we need to write a program that checks whether the kth bit of a number is either 1 or 0. In this lesson, we try to find a bit in the binary representation of a number at the kth position and check if

In this lesson, we use the Left Shift operator to find the bit length of a number. Introduction In this question, we take input and find its bit length. Problem Statement Given an input, find its bit length. Input: 8 Output: 4 (1000) Input: 2 Output: 2 (10) Input: 7

Essential Java 3D array best practices: implement proper bound checking, safe element access, and efficient traversal techniques. Learn to handle ArrayIndexOutOfBoundsException and NullPointerException with production-ready error handling code examples.

Learn Apache Maven essentials for Java developers. Master automated dependency management, standardized project structure, and build lifecycle. Discover why Maven is the preferred build tool for enterprise Java projects with hands-on examples.

Generate all possible subsets using bit manipulation: left shift operators, binary representation patterns. Master powerset algorithms for coding interviews. Asked by Apple, Microsoft, Amazon, Facebook with multi-language solutions.

Discover practical Java 3D array applications: RGB image processing, 3D game world development, and scientific data analysis. Real-world code examples demonstrate temperature tracking, voxel-based gaming, and multi-dimensional data handling.

Master Java 3D array traversal with complete guide covering triple-nested loops, enhanced for-each loops, and functional streams. Learn to efficiently navigate multi-dimensional data structures with practical code examples and complexity analysis.

Master XOR bitwise technique: a^a=0, a^0=a properties eliminate duplicates, leaving unique element. Linear O(n) time, constant O(1) space complexity. Perfect coding interview solution with multi-language implementations.

Find element appearing once while others appear twice. Master 4 approaches: brute force O(n²), HashTable O(n) space, mathematical formula, and optimal XOR bitwise O(1) space. Essential coding interview challenge.

Master XOR bit manipulation: a^a=0, a^0=a properties to find missing element. Single-loop optimization reduces operations from 2n to n. O(1) space complexity with multi-language implementations for coding interview success.

Master 3 approaches: HashSet O(n) space, mathematical summation n(n+1)/2 O(1) space, and XOR bitwise techniques. Find missing element from 0-N range with optimal algorithms for coding interviews and competitive programming.

Master string reversal with char arrays: two-pointer swap technique vs StringBuilder.reverse(). Learn in-place O(1) memory algorithms for coding interviews. Asked by Facebook, Apple, Amazon, Adobe with complete implementations.

Master in-place array reversal: swap elements using two pointers from start/end indices. Memory-efficient O(1) space complexity, no extra arrays needed. Essential for coding interviews and space optimization.

Master XOR bit manipulation: find element appearing odd times using a^a=0, a^0=a properties. O(n) time, O(1) space complexity. Simple yet powerful algorithm for coding interviews with multi-language implementations.

In this lesson, you will learn how immutability is achieved through functional programming.

Master 3D array element access: A[layer][row][column] syntax, zero-based indexing from A[0][0][0] to A[D-1][N-1][M-1]. Learn safe element modification and ArrayIndexOutOfBoundsException handling with practical examples.

Master 3D arrays: cube-like structures with layer[row][column] access patterns. Learn initialization methods, traversal techniques, memory optimization, and real-world applications like RGB images, game worlds, and scientific data modeling.

In this lesson, we use the XOR operator to swap the values of two inputs. Introduction In this question, input two numbers and swap them without using the swapping logic. Problem statement We need to write a program to swap two numbers. Input: a = 10, b = 121 Output: a = 121,

Introduction A Bitwise XOR is a binary operation that takes two-bit patterns of equal length and performs the logical exclusive OR operation on each corresponding bits pair. Each position’s result is 0 if both bits are 0 or if both bits are 1. Otherwise, the result is 1.

The Bitwise XOR operator is denoted by ^. When an XOR gate is given with 2 inputs, the corresponding outputs will be: If two input bits are different, the output is 1. In all other cases, it is 0. This is an introductory lesson on XOR. Introduction This operator is the

We make use of bit manipulation to solve this problem. using a NOT operator. In this coding question, we use the NOT operator to switch the sign of a number. Problem Statement We need to write a program to switch the sign of a number. Input: 10 Output: -10 Intuition

Bitwise NOT, takes the input number, considers its binary representation, and inverts every bit, which means the 0 bit becomes 1, and the 1 bit becomes 0. Introduction This article teaches us more about the NOT operator and how it will be used in computers. We also learn the 2&

The Bitwise NOT operator evaluates the binary representation of the value of a single input. If the bit contains 1, the output will be 0 for that bit location. If the bit contains 0, the output will be 1. Introduction This lesson introduces the tilde '~' character. This is

We need to write a program with minimum flips to make the two bits’ OR operation equal a number. If you understand the OR operations clearly, this problem will be a good challenge for your skills. If you understand the OR operations clearly, this problem will be a good challenge

Here, we will discuss the '|' operator in detail. Introduction A Bitwise OR is a binary operator that takes two-bit patterns of equal length and performs the logical inclusive OR operation on each corresponding bits pair. The result in each position is 0 if both bits are 0.

OR operator compares each bit of the first operand to the second operand’s corresponding bit. If both bits are 0, the corresponding result bit is set to 0. Otherwise, the corresponding result bit is set to 1 Let's see another Bitwise operator, 'OR'. This outputs

Let's solve this using brain kernighan's algorithm. This is optimized to O(1) time and space. Let's see how we use Brain Kernighan's algorithm to achieve this. Solution review: Brian Kernighan’s algorithm We saw an algorithm to solve this problem in

We solve by making use of the & operator in computers. There are many ways to solve this, of which two approaches are simple, and one is a more complex but better solution. In this lesson, we will try to check if the given number is a power of 2.

This is a solution to another Bitwise question. Think of the rightmost bit of a number and think of some logic that could solve this. We solve using AND operator with O(1) time Complexity. Here, we see the solution for checking if a number is even/odd. Solution review

This is an example of another Bitwise question. Think of the rightmost bit of a number and think of some logic that could solve this. Introduction This is a classic question in Mathematics 🧮 for computers. Example: Inputs: 1, 3, 5, 7, ... Output: Odd Input: 2, 4, 6, 8, ... Output: Even

This is an extension to the previous problem counting the number of set bits or 1's present in a number. Introduction This is an extension of the previous counting set bits problem. Problem Statement Write a program to return an array of numbers of 1’s in the

This review provides a detailed analysis to solve the count set bits. Solution review We saw an algorithm to solve this problem in the previous lesson. Let’s see how to solve this more efficiently using Briann’s Algorithm. Brian Kernighan’s algorithm This is a faster execution than the

This is a traditional problem counting the number of set bits or 1's present in a number. Introduction Let’s see how we can count the set bits using the AND operator. What are set bits? 1 = set-bit 0 = unset-bit Example: Input: 5 Output: 0101 (in

Introduction A Bitwise AND is a binary operation that takes two equal-length binary representations and performs the logical AND operation on each pair of the corresponding bits. This is equivalent to multiplying them. Bitwise ANDing any number x with 0 yields 0 Bitwise AND The Bitwise AND operator does

Introduction Bitwise AND is the most commonly used logical Bitwise operator. It is represented by a sign (&). AND operator is the same as the AND gate we studied in the chapter on digital electronics, as shown below: Sketch What is the Bitwise AND operator? The Bitwise AND operator is

We use the modulo and division method, and we calculate the binary representation of a decimal number. Let’s represent the binary by considering the remainder column from bottom to top. In this article, we will write the code to count the number of bits present for a given input.

This is an example problem for counting digits in an integer. Solving this problem helps you find the place values and how they are represented in the decimal number system. Let’s see some approaches we can take to solve this algorithmic problem. Approach How to count the number of

This article will help you understand Bitwise operators and how to use them by giving practical examples. Why use Bitwise operators? In computer programming, a Bitwise operation operates on one or more bit patterns or binary numerals at the bit level. Advantages * They are fast and simple actions. * The processor

In mathematics and digital electronics, a binary number is expressed in the base-2 number system, using only two symbols: "0" and "1". What is the binary number system? Another number system that became famous after the decimal is the binary number system, which has only

In this lesson, you will learn everything about the Decimal number system. The decimal number system is the standard system for denoting integer and non-integer numbers.

This lesson will be an introduction to number systems. Here we see the different types of number systems that are represented in mathematics.

In this lesson, you will learn how to manipulate individual bits in binary data using bitwise operators. Learn fundamental concepts, practical applications, and why bit manipulation is essential for efficient algorithms and coding interviews.

Learn bit manipulation fundamentals and bitmask techniques from scratch. This comprehensive introduction covers binary operations, bitwise operators, and essential algorithms. Perfect for beginners preparing for coding interviews and competitive programming challenges.

Detect duplicate elements using HashSet: O(n) time complexity, single-pass iteration. Handles negative numbers, empty arrays, and multiple duplicates. Essential algorithm for coding interviews with complete implementation.

Learn to count array elements with even digits: division, logarithmic log10(N), recursive, and string methods. Master place values, decimal system concepts, and digit counting algorithms for coding interviews.

Learn to detect monotonic arrays: increasing A[i] ≤ A[j] or decreasing A[i] ≥ A[j] sequences. Master two-pass vs optimized one-pass O(n) solutions using boolean flags. Essential for coding interviews and array validation.

Master array search techniques: Linear search for unsorted arrays O(n) vs Binary search for sorted arrays O(log n). Learn implementation, complexity analysis, and when to use each algorithm with complete Java examples.

Learn optimal algorithm to find maximum value in array: O(n) single-pass iteration vs inefficient O(nlogn) sorting approach. Handles edge cases, empty arrays, and sorted/unsorted inputs with complete Java implementation.

Master the classic Two Sum algorithm: find array indices that sum to target. Learn brute force O(n²) vs HashMap O(n) solutions. Asked by Amazon, Apple, Netflix, Microsoft in coding interviews.

Learn to access 2D arrays: traditional for-loops, Arrays.deepToString(), and enhanced for-each loops. Master row-column traversal patterns, O(N×M) complexity analysis, and efficient matrix element printing techniques.

Master 2D arrays: "arrays within arrays" with grid structure. Learn declaration syntax, row[column] indexing, initialization methods, and ArrayIndexOutOfBoundsException handling. Perfect for matrices, grids, and table data structures.

Test dynamic array resizing: start with capacity 4, auto-expand to 8, then 16 as elements added. Learn size doubling algorithm, memory allocation, and practical testing of custom resizable array data structure.

Master dynamic array complexities: O(1) amortized insert, O(n) worst-case resize, O(1) access/delete-end, O(n) middle operations. Learn space complexity, memory allocation patterns, and performance optimization strategies.

Learn how to convert fixed-size Java arrays to dynamic resizable arrays. Step-by-step guide covers array resizing implementation, memory management, and complete code examples for creating ArrayList-like data structures.

Master dynamic arrays: auto-resizing when capacity exceeded, O(1) lookups, cache-friendly storage. Learn ArrayList foundations, size doubling, costly O(n) inserts/deletes, and when to choose dynamic over fixed arrays.

Learn to test custom Array class: verify insert(), remove(), get(), size() operations. Understand capacity vs size differences with practical examples. Complete data structure testing guide for robust code validation.

Step-by-step guide to implement Array class: insert(), remove(), get(), size(), print() methods. Learn error handling, element shifting, and IndexOutOfBoundsException management. Perfect for data structure mastery.

Learn to implement array operations: insert, delete, get, size, and print elements. Master fixed-size to dynamic array conversion with step-by-step coding examples. Essential for understanding ArrayList and LinkedList internals.

Master array element removal: O(1) end deletion vs O(n) start/middle deletion. Learn left-shifting techniques, gap filling, and performance optimization with step-by-step code examples for efficient array operations.

Master array insertion techniques: O(1) end insertion vs O(n) start/middle insertion. Learn element shifting, space allocation, and dynamic array modification with step-by-step code examples for coding interviews.

Master array performance: O(1) access/append, O(n) insertion/deletion, O(log n) binary search. Learn worst-case scenarios, memory allocation costs, and optimization strategies for coding interviews and algorithm design.

Master array trade-offs: O(1) fast lookups and appends vs O(n) costly inserts/deletes. Learn fixed-size limitations, memory waste, cache friendliness, and when to choose arrays for optimal performance.

Learn the crucial difference: Array capacity = maximum items it can hold, Array length = current items stored. Master A.length attribute, memory allocation, and avoid common coding mistakes with practical examples.

Learn array fundamentals: contiguous memory storage, zero-based indexing, declaration methods, and RAM representation. Master array access patterns, avoid ArrayIndexOutOfBoundsException, and understand O(N) complexity with code examples.

Discover why arrays replaced individual primitive variables in Java. Learn how arrays solve memory management challenges, store millions of values efficiently, and optimize data access. Essential knowledge for Java developers and coding interviews.