    <!DOCTYPE html>
    <html>
    <head>
      <meta charset="UTF-8">
      <title>prompt()로 사용자 입력받기</title>
      <link rel="stylesheet" href="style_js.css">
    <body>
      <script>
        let num, add;
        num = prompt("숫자를 입력하세요");
        document.write("num: " + num + "<hr>");
        add = num + 22;
        document.write("num + 22: " + add + "<hr>");
        num = parseInt(num);
        add = num + 22;
        document.write("parseInt + 22: " + add);
      </script>
    </body>
    </html>