scope.js

(function (scope) {
    var privateStaticProperty = null;

    var privateStaticMethod = function () {
        console.log("private hello");
    };

    var PublicClass = function () {
        var self = this;

        var privateProperty = null;

        var privateMethod = function () {
        };

        self.publicProperty = null;

        self.publicMethod = function () {
            console.log("public hello: " + self.publicProperty);
        };

        // do something here (constructor)
        privateStaticMethod();

        return self;
    };

    // demo method
    PublicClass.prototype.getPrivateStaticProperty = function () {
        return privateStaticProperty;
    };

    // demo method
    PublicClass.prototype.setPrivateStaticProperty = function (value) {
        privateStaticProperty = value;
    };

    scope.PublicClass = PublicClass;
}).call(this, global); // `global` is for NodeJS


// Here starts the demo

var foo = new PublicClass();
var bar = new PublicClass();

console.log(foo.getPrivateStaticProperty());
console.log(bar.getPrivateStaticProperty());

foo.setPrivateStaticProperty("hello world");

console.log(foo.getPrivateStaticProperty());
console.log(bar.getPrivateStaticProperty());

foo.publicProperty = 1;
bar.publicProperty = 2;

foo.publicMethod();
bar.publicMethod();