Java class set. Traversal output

public static void main(String[] args) {
		List<Character> arrayList = new ArrayList<Character>();
		arrayList.add('a');
		arrayList.add('b');
		arrayList.add('c');
		arrayList.add('d');// add elements

		// loop over the output
		for (int i = 0; i < arrayList.size(); i++) {
			System.out.print(arrayList.get(i) + " ");
		}
		
		System.out.println();

		// Traverse the output (reverse)
		// Although the output is reversed, the original data of the List has not changed
		for (int i = arrayList.size() - 1; i >= 0; i--) {
			System.out.print(arrayList.get(i) + " ");
		}

		// convert to object array
		Character[] chs = arrayList.toArray(new Character[] {});
		// loop over the output
		for (int i = 0; i < chs.length; i++) {
			System.out.println(chs[i]);
		}