Is Java a Compiled or Interpreted Programming Language?

How does the Java programming language work in terms of compilation and interpretation?

Java is both a compiled and an interpreted programming language. This duality is a key feature of Java that enables it to run on multiple platforms without modification. Here’s a detailed breakdown of how Java code is executed:

// Example Java program
public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
} // Save this as HelloWorld.java

Causes

• Java source code is written in plain text files with a `.java` extension.
• The Java compiler, `javac`, converts the source code into bytecode, which is stored in `.class` files.
• The Java Virtual Machine (JVM) interprets the bytecode and executes it on the host machine.

Solutions

• To run Java code, first compile the source file using `javac`. For example: `javac HelloWorld.java`.
• After compilation, run the program using the `java` command, for example: `java HelloWorld`.
• The JVM executes the bytecode, handling the translation to native machine code at runtime.

Mistake: Forgetting to compile the Java file before running it.

Solution: Always run the javac command to compile your Java program before executing it.

Mistake: Assuming Java is purely interpreted like some other languages, leading to performance misconceptions.

Solution: Understand that Java uses a compilation step to bytecode before interpretation by the JVM, providing better performance than true interpreters.