Question

In javascript you can call a function as a function or as a constructor. For example you can do :

myObject = new Number(13);
myPrimitiveValue = Number(13);

or simply

myPrimitiveValue = 13;

I understand the difference between the results. Can you explain me under which reasonable circumstances creating a number, a boolean or a string as an object is desirable? For example, ability to set new properties (this is something you can do on objects but can’t really do on primitive values) is almost always a bad idea for objects containing number/boolean/string. Why would I want a numeric/boolean/string object?

Answer 1

You rarely have to create objects for the basic data types.

From the Microsoft documentation of the Number object:

“The Number object is a wrapper for
numeric data. The primary purposes for
the Number object are to collect its
properties into one object and to
allow numbers to be converted into
strings via the toString method. The
Number object is similar to the
Number data type. However, they have
different properties and methods.

You rarely need to construct a Number
object explicitly. The Number data
type should be used in most
circumstances. Since the Number object
interoperates with the Number data
type, all Number object methods and
properties are available to a variable
of type Number.”