Why declare 'new'?

[lordvader]

I've just started learning js by reading Learning JavaScript by Shelley Powers. It's okay I guess... I'm through 4 chapters.

Anyways, there's this explanation of declaring new instances of objects. My question is, what's that for?

Chapter 4.1:

 

var holdAnswer = new Boolean(true);

 

This is the only line of the example... so isn't holdAnswer already a new variable?

So why use 'new'? The book only says you can do it, but not why.

Thanks

[RichardRotterdam]

actually in javascript you dont have to do that you only say holdAnswer is of a type boolean you can do the same with arrays

myArray=new Array();

but for a boolean isnt really needed

[lordvader]

Yes but what's the purpose of using 'new'?

[RichardRotterdam]

its either for creating an object or setting the type of a variable

[lordvader]

But why do i need to use 'new' to create an object or set the type of variable?

What is the difference between

 

var first = array()

 

and

 

var first = new array()

[wrongmove18]

Because you are instantiating the function or class to a variable.

[wrongmove18]

But why do i need to use 'new' to create an object or set the type of variable?

What is the difference between

 

var first = array()

 

and

 

var first = new array()

 

You can call Array() as a predefined class of javascript.

 

var first = new Array();

 

It means you a creating a new instance of the class Array.