[프로그래머스/Java] 대소문자 바꿔서 출력하기

-Code

import java.util.Scanner;

public class Solution {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        StringBuffer sb = new StringBuffer();

        for(char w : a.toCharArray()) {
            if (Character.isUpperCase(w)) {
                sb.append(Character.toLowerCase(w));
            } else {
                sb.append(Character.toUpperCase(w));
            }
        };

        System.out.println(sb);
    }
}