[알고리즘문제풀기] 대문자와 소문자

문제

내가 작성한 정답

class Solution {
    public String solution(String my_string) {
        String answer = "";
        for(char c: my_string.toCharArray()){
            if(Character.isLowerCase(c)) answer += ""+Character.toUpperCase(c);
            else answer += ""+Character.toLowerCase(c);
        }
        return answer;
    }
}

다른 사람들의 정답

import java.util.stream.Collectors;

class Solution {
    public String solution(String myString) {
        return myString.chars().mapToObj(operand -> String.valueOf((char) (Character.isLowerCase(operand) ? Character.toUpperCase(operand) : Character.toLowerCase(operand)))).collect(Collectors.joining());
    }
}

class Solution {
    public String solution(String s) {
        String answer = "";

        for(int i=0;i<s.length();i++){
            if(s.charAt(i)>=97 && s.charAt(i)<=122){
                answer += (char)(s.charAt(i)-32);
            } else if(s.charAt(i)>=65 && s.charAt(i)<=90){
                answer += (char)(s.charAt(i)+32);
            } else {
                answer += s.charAt(i);
            }
        }

        return answer;
    }
}