Every Java concept explained in depth — from variables to multithreading, Spring Boot, JDBC, and beyond.
public class Main { public static void main(String[] args) { // Java 21 – Virtual Threads var greeting = "Welcome to Java! 🚀"; System.out.println(greeting); for (int i = 1; i <= 5; i++) { System.out.println("Step " + i + " ✓"); } } }
Click any topic to dive in with full explanations and programs
History, features, JVM/JDK/JRE, platform independence
Install JDK, compile & run, program structure
Primitives, type casting, literals, var keyword
Arithmetic, relational, logical, bitwise, ternary
Conditional logic, nested if, switch expressions
for, while, do-while, for-each, break, continue
1D & 2D arrays, sorting, searching, Arrays class
Class anatomy, object creation, methods, static members
Default, parameterized, copy constructor, this keyword
extends, super keyword, method overriding, types
Overloading, overriding, dynamic dispatch, instanceof
Abstract classes, abstract methods, design patterns
Access modifiers, getters/setters, data hiding
interface keyword, default methods, functional interfaces
String methods, StringBuilder, StringBuffer, regex
try-catch-finally, custom exceptions, checked/unchecked
List, Set, Map, Queue, Iterator, Comparable
Generic classes, methods, wildcards, bounded types
Lambda expressions, Stream API, filter, map, reduce
Thread class, Runnable, synchronization, ExecutorService
File class, streams, BufferedReader, NIO, serialization
Lambdas, Streams, Optional, Date/Time API, default methods
Records, Sealed classes, Text Blocks, Pattern Matching
Virtual Threads, Record Patterns, Sequenced Collections
Value Classes, Stream Gatherers, Structured Concurrency
Connections, PreparedStatement, ResultSet, transactions, pooling
IoC container, Dependency Injection, Beans, AOP
Auto-configuration, starters, Actuator, REST API
Controllers, REST APIs, request mapping, validation
JPA entities, Hibernate ORM, JpaRepository, JPQL
Architecture, Eureka Service Discovery, API Gateway, Feign, Resilience4j
From writing test cases and bug reports to Selenium, TestNG, BDD Cucumber, API testing, and CI/CD pipelines.
@Test public void loginTest() { driver.get("https://app.example.com"); driver.findElement(By.id("username")) .sendKeys("admin"); driver.findElement(By.id("password")) .sendKeys("pass123"); driver.findElement(By.id("login")).click(); Assert.assertEquals( driver.getTitle(), "Dashboard"); }
From manual test cases to Selenium, API testing, BDD, and CI/CD pipelines
SDLC, STLC, types of testing, black/white/grey box
Test plan, test strategy, test cases, RTM
Equivalence partitioning, boundary values, decision tables
Bug reporting, severity, priority, JIRA workflow
Browser automation, locators, waits, Actions class
Annotations, test suites, data providers, reporting
Design pattern, PageFactory, maintainable test framework
Postman, Rest Assured, JSON validation, status codes
Gherkin syntax, feature files, step definitions, hooks
Jenkins, GitHub Actions, Maven/Gradle integration
Prompt Engineering, LLMs, Generative AI for QA, AI Agents, MCP Server, Selenium AI
Cross-browser testing, auto-waiting, parallel execution, CI/CD integration, real-world projects
Model-based testing, Tosca Commander, modules, XScan, TestCase creation, enterprise execution
Build powerful, scalable single-page applications with Angular, TypeScript, RxJS, Angular Material, and NgRx.
@Component({ selector: 'app-root', template: ` <h1>{{ title }}</h1> <ul> <li *ngFor="let item of items"> {{ item }} </li> </ul> ` }) export class AppComponent { title = 'Angular App 🅰️'; items = ['Component','Service','Router']; }
Build enterprise-grade SPAs with Angular, TypeScript, RxJS, and Angular Material
Angular CLI, project structure, modules, bootstrapping
Types, interfaces, decorators, classes, generics
@Component, lifecycle hooks, input/output, ViewChild
Interpolation, property/event binding, ngIf, ngFor, ngClass
Injectable services, DI hierarchy, providedIn
RouterModule, lazy loading, route guards, child routes
FormBuilder, FormControl, validators, FormArray
HttpClientModule, Observables, interceptors, error handling
Built-in pipes, custom pipes, pure vs impure pipes
Material components, state management, Store, Effects
Build blazing-fast, reactive UIs with React Hooks, Redux Toolkit, React Router, Axios, and testing with Jest & RTL.
import { useState } from 'react'; function Counter() { const [count, setCount] = useState(0); return ( <div> <h2>Count: {count}</h2> <button onClick={() => setCount(count + 1)}> +1 </button> </div> ); }
Build modern, reactive UIs with React Hooks, Redux Toolkit, and React Router
What is React, CRA/Vite setup, JSX basics, Virtual DOM
Functional components, class components, component tree
Passing data, useState, lifting state, controlled components
SyntheticEvents, forms, list rendering, keys
useState, useEffect, cleanup, dependency array
useContext, useReducer, useMemo, useCallback, useRef
BrowserRouter, Routes, Link, useNavigate, dynamic routes
fetch, Axios, async/await, loading states, error handling
Store, slices, createAsyncThunk, useSelector, useDispatch
Jest, React Testing Library, mocking, snapshot testing