Using the new keyword

new.js

var str = new String('Hello world');
/*******
You could do the above, but it's best to avoid it (instead do like the variable str2 below)
(because JavaScript knows that anything inside single or double quotes has the type of String)

Same goes for other primitives. This is for example purposes only. 

NOTE: To clarify -- the only time I ever use the new keyword in practice is when I use a function constructor and create my own object type.
*******/

var str2 = 'Hello world';
// both have the prototype of String and inherit all the String methods and properties