List<String> list = new ArrayList<>(Arrays.asList("A", "B", "C"));
list.set(1, "D");
System.out.println(list); // ์ถ๋ ฅ: A, D, C
List<String> list = new ArrayList<>(Arrays.asList("A", "B", "C"));
list.set(list.indexOf("A"), "O");
System.out.println(list); // ์ถ๋ ฅ: O, B, C