JAVA Beginner ~55 h 1 students enrolled

Java

Complete Java course: from variables and OOP to collections, streams, generics and real projects. One of the most in-demand languages in the world.

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42 lessons
15 exercises
3830 XP for course
~55 h

What You'll Learn

Introduction to Java
Variables and Types
Strings
Numbers and Math
Conditions
Loops
Arrays
Methods
Classes and Objects
Inheritance
Interfaces
Collections: List
Map and Set
Exception Handling
Lambda Expressions
Stream API
Generics
Enum and Record
Files and I/O
Multithreading
Optional
Annotations
Testing
Design Patterns
Maven and Gradle
Project: Calculator
Project: Library
Project: REST API
Java Cheat Sheet
What's Next?

This Course Includes

Interactive exercises with instant feedback
Real compiler in your browser
Certificate upon completion
Gamification: XP, levels, badges

Curriculum

30 lessons · 42 lessons · 15 exercises

1

Introduction to Java

What is Java, history, first program

  • What is Java? +10 XP
  • Hello World in Java +10 XP
2

Variables and Types

Primitive types, declaration, type casting

  • Variables in Java +10 XP
  • Practice: Variables +10 XP
3

Strings

String, StringBuilder, string methods, formatting

  • Strings in Java +10 XP
  • Practice: Strings +10 XP
4

Numbers and Math

Arithmetic, Math, casting, wrappers

  • Numbers in Java +10 XP
5

Conditions

if/else, switch, ternary operator

  • Conditions in Java +10 XP
  • Practice: Conditions +10 XP
6

Loops

for, while, do-while, for-each, break/continue

  • Loops in Java +10 XP
  • Practice: Loops +10 XP
7

Arrays

1D, 2D arrays, Arrays class, sorting

  • Arrays in Java +10 XP
  • Practice: Arrays +10 XP
8

Methods

Declaration, params, return, overloading, varargs

  • Methods in Java +10 XP
  • Practice: Methods +10 XP
9

Classes and Objects

Definition, constructors, this, getters/setters

  • Classes and Objects +10 XP
  • Practice: Classes +10 XP
10

Inheritance

extends, super, method overriding, abstract classes

  • Inheritance +10 XP
11

Interfaces

interface, implements, default methods, multiple implementation

  • Interfaces +10 XP
  • Practice: Interfaces +10 XP
12

Collections: List

ArrayList, LinkedList, List methods, Collections

  • List in Java +10 XP
  • Practice: List +10 XP
13

Map and Set

HashMap, TreeMap, HashSet, TreeSet

  • Map and Set +10 XP
14

Exception Handling

try/catch/finally, throws, custom exceptions

  • Exceptions +10 XP
  • Practice: Exceptions +10 XP
15

Lambda Expressions

Lambdas, functional interfaces, Predicate, Consumer, Function

  • Lambdas +10 XP
16

Stream API

filter, map, reduce, collect, flatMap

  • Stream API +10 XP
  • Practice: Streams +10 XP
17

Generics

Type parameters, bounded types, wildcards

  • Generics +10 XP
18

Enum and Record

Enums, records, sealed classes

  • Enum and Record +10 XP
19

Files and I/O

Files, Path, BufferedReader, NIO

  • Files and I/O +10 XP
20

Multithreading

Thread, Runnable, synchronized, ExecutorService

  • Multithreading +10 XP
21

Optional

Optional, null safety, Optional methods

  • Optional +10 XP
22

Annotations

@Override, @Deprecated, custom annotations

  • Annotations +10 XP
23

Testing

JUnit, assert, @Test, @BeforeEach, Mockito

  • Testing +10 XP
24

Design Patterns

Singleton, Factory, Observer, Builder, Strategy

  • Design Patterns +10 XP
25

Maven and Gradle

Build tools, dependencies, pom.xml, build.gradle

  • Maven and Gradle +10 XP
26

Project: Calculator

OOP calculator with error handling

  • Calculator +10 XP
27

Project: Library

OOP system with collections and streams

  • Library +10 XP
28

Project: REST API

Spring Boot, controllers, services, REST

  • REST API with Spring Boot +10 XP
29

Java Cheat Sheet

Cheat sheet for all course topics

  • Java Cheat Sheet +10 XP
30

What's Next?

Where to go after the course

  • What's Next? +10 XP

Requirements

No prior knowledge required — we start from scratch

Course FAQ

Do I need programming experience?
Not at all! This course is built for complete beginners. We start from the basics and gradually increase complexity.
How do lessons work?
Each lesson includes theory with examples and interactive exercises. You write code right in your browser, and our compiler checks the result.
How long does the course take?
On average, you can complete the course in a few days at 1-2 hours per day. But there's no rush — learn at your own pace.
Will I get a certificate?
Yes! After completing all lessons and exercises, you'll receive an electronic certificate with a unique ID.

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