[JS] Wzorzec modułu

var Rectangle = (function() {
    var constr,
        a,
        b;

    constr = function(a, b) {
        this.a = a;
        this.b = b;
    }
    constr.prototype = {
        getArea: function() {
            return this.a * this.b;
        },
        getPerimeter: function() {
            return 2 * (this.a + this.b);
        }
    }
    return constr;
})();