// Java source file: HelloWorld.java
public class HelloWorld {
    public static void main(String[] args) {
        String message = "Hello, Bytecode Explorer!";
        System.out.println(message);
        int sum = add(5, 7);
        System.out.println("Sum: " + sum);
    }

    public static int add(int a, int b) {
        return a + b;
    }
}

// Compile the Java source file
// javac HelloWorld.java

// Disassemble the compiled class file to show bytecode instructions
// javap -c HelloWorld.class

// Disassemble with verbose output, showing constant pool and stack details
// javap -v HelloWorld.class

// Example javap -c output snippet for 'add' method:
// public static int add(int, int);
//   Code:
//      0: iload_0
//      1: iload_1
//      2: iadd
//      3: ireturn

// Example javap -c output snippet for 'main' method (partial):
//   Code:
//      0: ldc           #2                  // String "Hello, Bytecode Explorer!"
//      2: astore_1
//      3: getstatic     #3                  // Field java/lang/System.out:Ljava/io/PrintStream;
//      6: aload_1
//      7: invokevirtual #4                  // Method java/io/PrintStream/println:(Ljava/lang/String;)V
//     10: iconst_5
//     11: iconst_7
//     12: invokestatic  #5                  // Method add:(II)I
//     15: istore_2

// Java source file: ConditionalLoop.java
public class ConditionalLoop {
    public static void process(int limit) {
        for (int i = 0; i < limit; i++) {
            if (i % 2 == 0) {
                System.out.println("Even: " + i);
            } else {
                System.out.println("Odd: " + i);
            }
        }
    }
}

// Compilation:
// javac ConditionalLoop.java

// Disassembly for 'process' method:
// javap -c ConditionalLoop.class

// Java source file: PerformanceExample.java
public class PerformanceExample {
    public void stringConcatenation() {
        String result = "";
        for (int i = 0; i < 10; i++) {
            result += i; // Inefficient for repeated concatenations
        }
        System.out.println(result);
    }

    public void stringBuilderConcatenation() {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 10; i++) {
            sb.append(i);
        }
        System.out.println(sb.toString());
    }
}

// Disassemble both methods and compare:
// javap -c PerformanceExample.class

/* 
 * No direct code example here, as this section discusses concepts beyond javap's immediate scope.
 * Consider mentioning external libraries or JVM flags for deeper introspection.
 */