Javascript: IIFE example...

1-iife.js

var GO = (function(go) {
	
	go = go || {};
	
	go.init = function(x) {
	   
	   console.log(x);
	   
	};
	
	go.hello = function(msg) {
	   
	   console.log('Hello: ' + msg);
	   
	};
	
	return go;
	
}(GO || {}));

GO.init('blah');

GO.hello('Billy');

2-iife-alt.js

var GO = (function(go) {
	
	// We've already determined if GO is defined, so no need to do the same thing here, right?
	
	go.init = function(x) {
	   
	   console.log(x);
	   
	};
	
	go.hello = function(msg) {
	   
	   console.log('Hello: ' + msg);
	   
	};
	
	return go;
	
}(GO || {})); // Pass GO if defined, otherwise pass empty object.

3-iife-new.js

var GO = (function(go) {
	
	go = go || {}; // Do our check here.
	
	go.init = function(x) {
	   
	   console.log(x);
	   
	};
	
	go.hello = function(msg) {
	   
	   console.log('Hello: ' + msg);
	   
	};
	
	return go;
	
}(GO)); // Cleaner! Thanks @preaction! :)

GO.init('blah');

GO.hello('Billy');

From @preaction via IRC:

in that exact instance you could remove either, but removing the outer one is safer, because it's closer to where the problem would occur if go was ever not an object

Thanks!!!!!

An awesome singleton example can be found here.