    <!DOCTYPE html>
    <html>
    <head>
      <meta charset="UTF-8">
      <title>for-in으로 개별 속성에 접근하기</title>
      <link rel="stylesheet" href="style_js.css">
    <body>
      <script>
        let person = new Object();
        person.name = "cho";
        person.age = 23;
        person.weight = 70;

        for(let prop in person) {
          document.write(prop + ": " + person[prop] + "<hr>");
        }
      </script>
    </body>
    </html>