What's the point of .slice(0) here?

Question

I was studying the jQuery source when I found this (v1.5 line 2295):

namespace = new RegExp(\"(^|\\\\.)\" +
  jQuery.map( namespaces.slice(0).sort(), fcleanu         


        

Answer 1

In addition to what @Anon said:

The slice() method selects the elements starting at the given start argument, and ends at, but does not include, the given end argument.

Example1:

var fruits = ["Banana", "Orange", "Lemon", "Apple", "Mango"];
var citrus = fruits.slice(1, 3);

The result of citrus will be:

Orange,Lemon

Example2:

var fruits = ["Banana", "Orange", "Lemon", "Apple", "Mango"];
var citrus = fruits.slice(-3, -1);

The result of citrus will be:

Lemon,Apple

Further information can be found here.