JS For in Loop

 
<!DOCTYPE html>
<html>
<head>
  <title>JavaScript</title>
  <script>
    var obj = {
      firstName : "Yahoo",
      lastName : "Baba",
      Age : 25,
      email : "hello@yahoobaba.net"
    };

    for(var key in obj){
      document.write(key + " : " + obj[key] + "<br>");
    }
  </script>
</head>
<body>
</body>
</html>