Creating private instance members using Object.create

by dsjbirch

JavaScript

function Container(param) {

    function dec() {
        if (secret > 0) {
            secret -= 1;
            return true;
        } else {
            return false;
        }
    }

    this.member = param;
    var secret = 3;
    var that = this;

    this.service = function () {
        return dec() ? that.member : null;
    };
}

var first = new Container("private");

var second = Object.create(first);

document.write(first.service() + "<br/>");
document.write(first.service() + "<br/>");
document.write(first.service() + "<br/>");
document.write(first.service() + "<br/>");

document.write(second.service() + "<br/>");
document.write(second.service() + "<br/>");
document.write(second.service() + "<br/>");
document.write(second.service() + "<br/>");