This project focuses on debugging a non-compilable Java program. The objective was to identify, analyze, and comment out lines that cause compilation errors or violate task constraints, ensuring the program runs without.

As per the assignment instructions:

1. Identify and comment out all lines that prevent the code from compiling.
2. Ensure the program is executable.

The following issues were identified and resolved through code blocking:

• Variable Redeclaration: Attempting to declare multiple variables with the same name (number) in the same scope.
• Lack of Initialization: Trying to access a local variable (uninitialized) before assigning it a value.
• Type Mismatch: Assigning an integer value directly to a String variable without proper conversion.
• Unresolved Symbols: Referencing a variable (undeclaredVariable) that has never been defined.
• Unused Code: Removing empty declarations to follow Clean Code principles.

• Language: Java 23
• IDE: IntelliJ IDEA
• Concepts: Compilation lifecycle, variable scope, initialization, and strong typing.

The code was processed using IntelliJ IDEA to ensure strict adherence to Java syntax rules. All problematic lines are now documented with explanations for why they were disabled.

The implementation ensures that only the valid, required logic remains active:

package com.yurii.pavlenko;

/**
 * Task 4: Identifying and explaining compilation errors.
 */

public class Task_4_App {
    public static void main(String[] args) {

        int number = 10;

        // int number = 20;
        // Error: Variable redeclaration. In Java, you cannot declare two variables with the same name in the same scope.

        // int uninitialized;
        // Optimization: Unused variable. While the declaration itself is technically valid,
        // using it without initialization causes a compilation error (Variable might not have been initialized).
        // It is removed to comply with Clean Code principles as it serves no purpose.

        // System.out.println(uninitialized);
        // Error: Local variable not initialized. Local variables must be assigned a value before they can be read.

        // String text = 123;
        // Error: Type mismatch. Java is a strongly typed language; an 'int' cannot be directly assigned to a 'String' variable.

        // System.out.println(undeclaredVariable);
        // Error: Cannot resolve symbol. You cannot use a variable that has not been declared.

        System.out.println(number);
    }
}

This project is licensed under the MIT License.

Copyright (c) 2026 Yurii Pavlenko

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files...

License: MIT