jsPatterns.privateStatic.js

jsPatterns.privateStatic.js

// constructor
var Gadget = (function () {
    // static variable/property 
    var counter = 0,
        NewGadget;
    // this will become the
    // new constructor implementation 
    NewGadget = function () {
        counter += 1;
    };
    // a privileged method 
    NewGadget.prototype.getLastId = function () {
        return counter;
    };
    // overwrite the constructor 
    return NewGadget;
}()); // execute immediately Testing the new implementation: 
var iphone = new Gadget();
console.log(iphone.getLastId()); // 1 
var ipod = new Gadget();
ipod.getLastId(); // 2 
var ipad = new Gadget();
ipad.getLastId(); // 3

1. constructor function cannot be closure also, the nearest way to do is to turn it into immediate call function and define a new constructor function inside. This way enable both prototype and closure power.
   More often than not, constructor function define properties rather than variables, so that those properties can be passed to the new instantiated instance.

Another combination use of closure and constructor is initiate the constructor inside the closure. And use constructor property to "new" another instance.