⚙️ Java Compilation & Execution

? Quick Overview

Java programs follow a two-step process: compilation and execution. Source code written by the programmer is first converted into bytecode, which is then executed by the Java Virtual Machine (JVM).

? Key Concepts

Java source files use the .java extension
Compilation is done using the javac compiler
Compiled bytecode is stored in .class files
Execution is handled by the JVM using the java command

? Syntax & Theory

The Java compiler checks syntax errors and converts source code into platform-independent bytecode. This bytecode runs on any system that has a compatible JVM installed.

? View Code Example

// Simple Java program to demonstrate compilation and execution
class HelloJava {
public static void main(String[] args) {
System.out.println("Java Compilation and Execution");
}
}

▶️ Live Output / Explanation

Program Flow

Save file as HelloJava.java
Compile using: javac HelloJava.java
Run using: java HelloJava

Output: Java Compilation and Execution

✅ Tips & Best Practices

Class name must match the filename exactly
Always check for compilation errors before execution
Ensure JDK is properly installed and configured

? Try It Yourself

Modify the program to print your name
Add another class and try compiling both
Observe what happens if class name and file name differ