Toggle Case of a String

const s = "Hello World";
const result = s.split("").map(c =>
  c === c.toUpperCase() ? c.toLowerCase() : c.toUpperCase()
).join("");
console.log(result);

public class Main {
    public static void main(String[] args) {
        String s = "Hello World";
        StringBuilder sb = new StringBuilder();
        for (char c : s.toCharArray()) {
            if (Character.isUpperCase(c)) sb.append(Character.toLowerCase(c));
            else if (Character.isLowerCase(c)) sb.append(Character.toUpperCase(c));
            else sb.append(c);
        }
        System.out.println(sb.toString());
    }
}

fun main() {
    val s = "Hello World"
    val result = s.map {
        when {
            it.isUpperCase() -> it.lowercaseChar()
            it.isLowerCase() -> it.uppercaseChar()
            else -> it
        }
    }.joinToString("")
    println(result)
}

let s = "Hello World"
var result = ""
for c in s {
    if c.isUppercase {
        result += c.lowercased()
    } else if c.isLowercase {
        result += c.uppercased()
    } else {
        result.append(c)
    }
}
print(result)

void main() {
  String s = 'Hello World';
  String result = '';
  for (var c in s.split('')) {
    if (c == c.toUpperCase() && c != c.toLowerCase()) {
      result += c.toLowerCase();
    } else if (c == c.toLowerCase() && c != c.toUpperCase()) {
      result += c.toUpperCase();
    } else {
      result += c;
    }
  }
  print(result);
}

#include <iostream>
#include <cctype>
using namespace std;

int main() {
    string s = "Hello World";
    for (char &c : s) {
        if (isupper(c)) c = tolower(c);
        else if (islower(c)) c = toupper(c);
    }
    cout << s << endl;
    return 0;
}

#include <stdio.h>
#include <ctype.h>

int main() {
    char s[] = "Hello World";
    for (int i = 0; s[i]; i++) {
        if (isupper(s[i])) s[i] = tolower(s[i]);
        else if (islower(s[i])) s[i] = toupper(s[i]);
    }
    printf("%s\n", s);
    return 0;
}