JavaScript Patterns 3.7 Primitive Wrappers

Primitive value Types:number, String, Boolean, NULL, and undefined.

// a primitive number var n =console.log (typeof/ // a number object var New Number (+); Console.log (typeof//  "Object"  

One reason to use the wrapper objects are when you want to augment the value and persist state. Because Primitives is not objects, they cannot is augmented with properties.

//Primitive Stringvargreet = "Hello There"; //Primitive is converted to an object//In order to use the split () methodGreet.split (") [0];//"Hello" //attemting to augment a primitive isn't an errorGreet.smile=true; //But it doesn ' t actually worktypeofGreet.smile;//"undefined" 

When used without new, wrapper constructors convert the argument passed to them to a primitive value:

typeof // "Number" typeof // "Number" typeof Number (new//  "number"typeof//  "string"typeof  //  "boolean"