A bit of technology

The problem I'm talking about is that this way you can not have any private data and methods which means such objects are more like name spaces — not exactly what we want.

There is no such thing as private data in JavaScript, but you can freely create hidden methods and variables inside functions. Internal data is only visible inside the function it is created in. Another great feature we have in JavaScript is anonymous functions. So we can wrap "private" data and methods inside anonymous function, define our JSON singleton inside this function and throw a "pointer" to singleton to outer world. Look at the example:

var Singleton = // It will hold our singleton, don't forget "=" character :)

(function() { // Creates and runs anonymous function, its result is assigned to Singleton

    var privateData = 'Hello, world!' // Any variable inside function becomes "private"
    var counter = 0

    function processData() { // Any function becomes "private" too!
        counter++
    }

    var instance = { // This is a definition of our Singleton, it is also private, but we will share it later
        print: function() { // This will be our public method
            processData()
            alert(privateData + ' Called print() ' + counter + ' times.')
        }
    }

    return(instance) // And some simple magic - global variable Singleton transforms into our singleton!

})()

Now you can access your singleton using Singleton name. Just like that:

Singleton.print()

But why do examples from Wikipedia suck? First one is not a kind of singleton we want. I've already explained that. The second one suck because it has performance issues. On the other hand it provides lazy-loading and can be useful if that feature is a must.

So now you know the only correct way to implement singleton pattern in JavaScript with all the bells and whistles, without compromises, bugs and performance issues. Easy and effective