To use Boolean in JavaScript constructors, use JavaScript boolean constructor() method. It returns a reference to the Boolean function that created the instance's prototype.
Example
You can try to run the following code to learn how to use Booleans in Constructors
<html>
<head>
<title>JavaScript constructor() Method</title>
</head>
<body>
<script>
var bool = new Boolean( );
document.write("bool.constructor() is:"+bool.constructor);
</script>
</body>
</html>