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>