Using a Javascript namespace/singleton won't accept arguments passed to member method

Question

Code of horror:

var namespace = new function ()
{
    this.saySomething = new function( something )
    {
        console.log( something );
    };
}

namespace.saySomething( "whatever" );

This outputs "undefined" when I expected it to output "whatever". How come? And what would the fix be? My goal is nothing more than to have a namespace where I put some helper functions.

score 3 · Answer 1 · edited May 23 '17 at 12:24

3

new function is generally wonky. Rob W's answer is absolutely correct (+1'd), but I would personally go even further and remove all the newing:

var namespace = 
{
    saySomething: function( something )
    {
        console.log( something );
    }
}

namespace.saySomething( "whatever" );

If you want to be able to create distinct instances, do it the right way:

function Namespace() {}
Namespace.prototype.saySomething = function (something)
{
    console.log(something);
}

// Usage:
var foo = new Namespace();
foo.saySomething("Hallllooooo!");

...though you did say "singleton," so I'm guessing this isn't relevant to your goal.

edited May 23 '17 at 12:24

Community

1
1

answered Apr 26 '12 at 19:51

Matt Ball

354,903
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Thanx. Yeah you're right, the prototype object for me in this particular situation is a little bit overkill. And I never intended to create a full blown singleton pattern either. So that's why I mixed together the words in the topic like so: "namespace/singleton". Appreciate your answer! – Martin Andersson Apr 26 '12 at 20:11

score 2 · Answer 2 · answered Apr 26 '12 at 19:48

2

Remove new before function(something){...}. Currently, saySomething is an instance of the anonymous constructor.

answered Apr 26 '12 at 19:48

Rob W

341,306
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678

Oh but of course, can't believe I missed that. Been awake for too long. Thank you so much for a superfast answer! – Martin Andersson Apr 26 '12 at 19:55

score 2 · Accepted Answer · answered Apr 26 '12 at 19:52

2

You don't need to use new before the functions. new is only used for instantiating objects, when a constructor is already defined.

Your code should look like:

var namespace = {
    saySomething: function(something) {
        console.log(something);
    }
}

namespace.saySomething("whatever");

answered Apr 26 '12 at 19:52

slowpoison

586
3
20

I wouldn't use this method because somebody might use your namespace and can override and do namespace.saySomething = function( someotherthing ) { console.log( someotherthing ); /* and some more stuff here.*/ }. – vimdude Apr 29 '12 at 21:03

score 1 · Answer 4 · answered Apr 29 '12 at 21:08

I would use something like the following because you also want to make sure that namespace doesn't get overridden by some other code.

var namespace = (function() {
      return {
          saySomething: function(something) {
               console.log(something);
          }
      };
})();

namespace.saySomething("whatever");

score 0 · Answer 5 · answered Apr 26 '12 at 19:51

0

This should do it, sample http://jsfiddle.net/Jssxy/

var namespace = {
    saySomething : function(something) {
        console.log(something);
    }
}

namespace.saySomething( "whatever" );

answered Apr 26 '12 at 19:51

Sully

14,672
5
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79

Using a Javascript namespace/singleton won't accept arguments passed to member method

5 Answers5