Java Tutorials & Practice

This repository contains Java learning resources and code examples for core concepts:

• Classes & Objects
• Static methods and variables
• Interfaces
• Enums
• Collections (Lists, Sets, Maps)
• Inner/Outer Classes
• Exception Handling, etc.

🚀 How to Run

1. Clone this repo:

   git clone https://github.com/Griffins2005/java-tutorials.git
   cd java-tutorials

2. Compile all Java files in a package (example: objectsclasses):

   javac objectsclasses/*.java

3. Run the main class:

   java objectsclasses.Main

Tip: Always compile before running, and make sure the package in the file matches the folder.

🔑 Common Issues & Fixes

• FileNotFound/ClassNotFound:

  • Ensure the filename matches the class name (case-sensitive).
  • Compile from the parent directory, not inside the package folder.
  • Package name at the top matches the folder structure.

• Extension errors (.Java):

  • Use lowercase .java only.

• Syntax errors (; expected, etc.):

  • Double-check every line ends with ;
  • Pay attention to curly braces { } and parentheses ().

• Running classes without main method:

  • Only java packagename.Main if Main has public static void main(String[] args).

• Changing packages or class names:

  • Always refactor both filename and package/class lines together.

🛠️ Editing & Troubleshooting

• Use find . -name "*.class" -delete to clean up old class files.
• Use javac packagename/*.java to batch-compile.
• Use java packagename.Main to run the main class.
• If you get errors, carefully read the first error message for hints.

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🙌 Contributing

Pull requests are welcome. For significant changes, open an issue first to discuss what you would like to change.

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📚 References

• Official Java Documentation
• Learn Java Online
• Java Programming Cheatsheet (Princeton)

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Happy coding!
Griffins Lelgut