public class StringBufferDemo {

    public static void main(String[] args) {

        // Creating a StringBuffer object

        StringBuffer sb = new StringBuffer("Hello");

        // 1. append()

        sb.append(" World");

        System.out.println("After append: " + sb);

        // 2. insert()

        sb.insert(5, ",");

        System.out.println("After insert: " + sb);

        // 3. replace()

        sb.replace(5, 6, "!");

        System.out.println("After replace: " + sb);

        // 4. delete()

        sb.delete(5, 6);

        System.out.println("After delete: " + sb);

        // 5. deleteCharAt()

        sb.deleteCharAt(5);

        System.out.println("After deleteCharAt: " + sb);

        // 6. reverse()

        sb.reverse();

        System.out.println("After reverse: " + sb);

        

        // Reversing back to original for further operations

        sb.reverse();

        // 7. setCharAt()

        sb.setCharAt(5, '-');

        System.out.println("After setCharAt: " + sb);

        // 8. substring()

        String subStr = sb.substring(0, 5);

        System.out.println("Substring (0, 5): " + subStr);

        // 9. length()

        int length = sb.length();

        System.out.println("Length of StringBuffer: " + length);

        // 10. capacity()

        int capacity = sb.capacity();

        System.out.println("Capacity of StringBuffer: " + capacity);

        // Additional methods for better understanding

        // Ensure Capacity

        sb.ensureCapacity(50);

        System.out.println("New Capacity after ensureCapacity(50): " + sb.capacity());

        // Trim to Size

        sb.trimToSize();

        System.out.println("Capacity after trimToSize: " + sb.capacity());

    }

}