The function() constructor is used in JavaScript to create a new function object. The objects created are parsed when the function is created.
Example
You can try to run the following code to learn how to work with function() constructor
Live Demo
<html>
<body>
<script>
var num = new Function('p', 'q', 'r', 'return p * q * r');
document.write("Value after multiplication: "+num(5, 2, 9));
</script>
</body>
</html>