JavaScript multiple namespaces

Question

I have a large js file that I want to break into multiple namespaces.

1. Is this a good/bad approach vs keeping everything in one namespace?

2. In NAMESPACE_FIRST how do I call map build?

   var NAMESPACE_FIRST = {
       init:function() {
           alert("onload functions");
       },
       this.map:function() {
           this.length = 0;
       },
       this.map.prototype.build:function(){
           return this.length;
       }
   };
   
   
   var NAMESPACE_SECOND = {
       upload:function() {
             //do something
       },
       delete:function() {
             //do something
       }
   };
   
   
   $(function () {
       NAMESPACE_FIRST.init();
   });
   

Answer 1

Nice question!

Firstly, your JavaScript is a little erroneous. To achieve the effect I think you want, your first namespace should look like:

var NAMESPACE_FIRST = {

    init: function() {
        alert("onload functions");
    },
    map: function() {
        this.length = 0;

        NAMESPACE_FIRST.map.prototype.build = function() {
            alert("1");
            return this.length;
        }
    }
}

So, answering question 2, your onready will be something like:

$(function () {
    NAMESPACE_FIRST.init();

    var obj = new NAMESPACE_FIRST.map();
    obj.build();
}

Regarding question 1, I've no real opinion either way.