<!DOCTYPE html>
<html>
<body>
<p>Click the button to create a boolean object, then display it's constructor</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var bool = false;
var x = bool.valueOf();
document.getElementById("demo").innerHTML = x;
}
</script>
</body>
</html>