대소문자 바꿔서 출력하기

// javascript

const readline = require('readline');
const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});

rl.on('line', function (line) {
    const str = line.trim(); 
    const result = [];

    str.split('').forEach(char => {
        result.push(char === char.toUpperCase() ? char.toLowerCase() : char.toUpperCase());
    });

    console.log(result.join('')); 
}).on('close', function () {
    process.exit();
});

 

// typescript

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});

rl.on('line', function (line: string) {
    const str = line.trim();
    const result: string[] = [];

    str.split('').forEach(char => {
        result.push(char === char.toUpperCase() ? char.toLowerCase() : char.toUpperCase());
    });

    console.log(result.join(''));
}).on('close', function () {
    process.exit();
});