<!DOCTYPE html>
<html>
<head>
<title></title>
<script>
var a = 1234;
console.log(typeof a);
a = "abcd";
console.log(typeof a);
a = true;
console.log(typeof a);
a = function () { };
console.log(typeof a);
console.log(typeof false);
</script>
</head>
<body>
</body>
</html>