function solution(my_string) {
var answer = [];
for (let x of my_string) {
x === x.toLowerCase()
? answer.push(x.toUpperCase())
: answer.push(x.toLowerCase());
}
return answer.join("");
}
function solution(my_string) {
var answer = '';
for (let c of my_string) answer += c === c.toLowerCase() ? c.toUpperCase() : c.toLowerCase();
return answer;
}