Visual Java

Learn Java in simple English, with drawings that move step by step.

Two courses in one website:

• CS1 · Java Introduction: for beginners. Start from zero.
• CS2 · Java Intermediate: the next level, after CS1.

Every lesson shows the explanation on one side and an animated drawing on the other side. When you press Next, the drawing, the highlighted code line and the program output move together, so you can see what Java does.

▶ Open the course online: https://drs-0.github.io/visual-java/

You don't need to install anything. It works in any modern browser, on a computer or a phone.

العربية ⬇

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What is inside

73 lessons and 15 code challenges. In the menu on the left, choose CS1 or CS2.

CS1 · Java Introduction (8 modules, 29 lessons)

Module	Lessons
1. Java Basics	Hello, Java! · Your first program · print and println · Comments
2. Variables	What is a variable · Data types · Math operators · Increment and assignment
3. User Input	Getting input with Scanner · Reading numbers
4. Strings	Strings and joining · String methods · Escape characters
5. Conditions	if · if ... else · else if · Nested if · switch
6. Logical Operators	AND && · OR || · NOT ! and combining
7. Loops	while · for · do ... while · break and continue
8. Arrays	Creating arrays · Looping over an array · for-each · 2D arrays

CS2 · Java Intermediate (7 modules, 44 lessons)

Module	Lessons
1. Methods	What is a method · Parameters · Return values · Overloading · Recursion
2. Classes & Objects	Classes and objects · Attributes and behavior · Constructors · Access modifiers · Getters and setters · Value and reference types · static · The Math class · final · Packages
3. OOP Concepts	The four OOP ideas · Inheritance · super and constructors · Polymorphism · Overriding vs overloading · Abstract classes · Interfaces · Type casting · Upcasting and downcasting · Anonymous classes · Inner classes · equals()
4. Collections	Arrays review · ArrayList · LinkedList · HashMap · Sets · Sorting · Iterators
5. Exceptions	try / catch · Multiple catch and finally · throw, throws, checked and unchecked
6. Threads	What is a thread · Runnable · sleep() and join()
7. Scanner & Files	Scanner input · The File class · Reading a file · Writing a file

Features

• Simple English. Short sentences for learners at a middle level. Java words stay as they are: class, extends, ArrayList, try...
• Step-by-step drawings. Arrays with their index, flowcharts for if and loops, circuits for && and ||, class trees, stack and heap memory, HashMap buckets, exceptions flying to catch, thread timelines and more.
• Arabic hints. Hard English words have a dotted line. Point at one (or tap it on a phone) to see the Arabic meaning. You can turn the hints off.
• Quizzes after every lesson: multiple choice and fill-in-the-blank code.
• A code challenge at the end of every module, with a checker and a solution.
• One path: the last lesson of CS1 leads straight into CS2.
• Your progress is saved in your browser, for each course.
• Light and dark mode, following your system setting.
• Keyboard: use the ← and → keys to move through the steps.

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How to download and use it

Option 1: Use it online (easiest)

Open https://drs-0.github.io/visual-java/ and start learning.

Option 2: Download a ZIP file

1. On this page, click the green Code button.
2. Click Download ZIP.
3. Unzip (extract) the file.
4. Open the folder and double-click index.html. It opens in your browser.

Option 3: Clone with git

git clone https://github.com/drs-0/visual-java.git
cd visual-java

Then open index.html in your browser.

Optional: run a small local server

Opening index.html directly works. If your browser blocks something, run a local server from inside the folder:

python -m http.server 8000

Then open http://localhost:8000 in your browser.

Internet note: the page loads its fonts from Google Fonts. Without internet it still works, but it uses your system fonts.

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Project structure

visual-java/
├── index.html              the page: layout and all styles
├── js/
│   ├── app.js              the engine: drawings, code highlighting, quizzes, challenges, progress, CS1/CS2 tabs
│   ├── cs1-basics.js       CS1 Module 1
│   ├── cs1-variables.js    CS1 Module 2
│   ├── cs1-input.js        CS1 Module 3
│   ├── cs1-strings.js      CS1 Module 4
│   ├── cs1-conditions.js   CS1 Module 5
│   ├── cs1-logic.js        CS1 Module 6
│   ├── cs1-loops.js        CS1 Module 7
│   ├── cs1-arrays.js       CS1 Module 8
│   ├── m1-methods.js       CS2 Module 1
│   ├── m2-classes.js       CS2 Module 2
│   ├── m3-oop.js           CS2 Module 3
│   ├── m4-collections.js   CS2 Module 4
│   ├── m5-exceptions.js    CS2 Module 5
│   ├── m6-threads.js       CS2 Module 6
│   └── m7-files.js         CS2 Module 7
└── docs/                   screenshots for this README

No build step and no libraries. It is plain HTML, CSS and JavaScript.

Add or change a lesson

Each module file calls addModule({...}). Set track: 'cs1' or track: 'cs2' to choose the course. A lesson looks like this:

{
  id: 'c1-1',
  title: 'Hello, Java!',
  body: `<p>Text in HTML. Use {{word|ترجمة}} for an Arabic hint.</p>
~~~
code blocks go between ~~~ lines
~~~`,
  code: `the Java code shown next to the drawing`,
  steps: [
    { cap: 'What happens in this step', line: 3, out: 'printed text' }
  ],
  draw: function (k) {          // k = step number, returns the shapes for that step
    return [
      B('box', 30, 40, 200, 60, { title: 'main()', tone: 'blue' }),      // box
      B('if', 200, 30, 180, 90, { shape: 'diamond', title: 'x > 0 ?' }), // flowchart diamond
      T('txt', 30, 140, 'some text'),                                   // text
      A('arr', 230, 70, 320, 70, { label: 'call' }),                    // arrow
      P('ptr', 100, 200, 'i = 0')                                       // pointer
    ];
  },
  quiz: [
    { q: 'Question?', options: ['A', 'B'], answer: 0, why: 'Because...' },
    { type: 'fill', q: 'Fill it in', code: 'int x = ___;', answer: ['5'] }
  ]
}

Shapes with the same id in two steps slide smoothly from the old place to the new one.

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Credits

The topics follow the outlines of the Sololearn courses Introduction to Java (CS1) and Java Intermediate (CS2). All lessons, drawings and questions in this project are written new, in simple English. This project is not made by Sololearn and is not connected to Sololearn.

License

The code is under the MIT License. You can use it, change it and share it.

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بالعربي

تعلّم Java بإنقليزي بسيط، مع رسومات تتحرك خطوة بخطوة.

كورسين في موقع واحد:

• CS1 · Java Introduction: للمبتدئين، تبدأ من الصفر.
• CS2 · Java Intermediate: المستوى اللي بعده.

من القائمة اللي على اليسار تختار CS1 أو CS2. وآخر درس في CS1 يوديك على طول لأول درس في CS2.

▶ افتح الكورس أونلاين: https://drs-0.github.io/visual-java/

ما يحتاج تثبّت أي شي. يشتغل على أي متصفح، بالكمبيوتر أو بالجوال، ومتى ما تبي.

المميزات

• 73 درس و 15 تحدي كود.
• إنقليزي بسيط، وأسماء Java باقية زي ما هي.
• رسومات تتحرك:
  • أراي جنب كل خانة الـ index حقها، وفيه سهم ينزل كل ما يزيد i.
  • مخططات انسيابية للـ if واللوبات.
  • دوائر كهربائية للـ && و ||.
  • شجرة الكلاسات للـ inheritance، والذاكرة، والـ HashMap، وغيرها.
• ترجمة عربية: الكلمات الصعبة تحتها خط منقّط. وقف عليها بالماوس أو اضغط عليها بالجوال وتطلع ترجمتها.
• أسئلة بعد كل درس، وتحدي كود بآخر كل قسم.
• يحفظ تقدمك على المتصفح.

طريقة التنزيل

الطريقة 1، الأسهل: افتح الرابط فوق وابدأ على طول.

الطريقة 2، تنزيل ZIP:

1. اضغط الزر الأخضر Code بأعلى الصفحة.
2. اختر Download ZIP.
3. فك الضغط عن الملف.
4. افتح المجلد واضغط مرتين على index.html. بيفتح لك بالمتصفح.

الطريقة 3، بـ git:

git clone https://github.com/drs-0/visual-java.git

بعدها افتح index.html بالمتصفح.

ملاحظة: الخطوط تنزل من الإنترنت. إذا ما فيه نت، الموقع يشتغل عادي بس بخطوط الجهاز.

تنبيه

المواضيع ماشية على نفس ترتيب كورسات Sololearn، وهي Introduction to Java و Java Intermediate. بس كل الشرح والرسومات والأسئلة مكتوبة من جديد. المشروع مو تابع لـ Sololearn.