CSharp mimicking JavaScript design pattern
Simplest C# code so far I can think of equivalent to the JavaScript design pattern to allow private members.
The original JavaScript code can be found here:
http://www.crockford.com/javascript/private.html
For the ease of comparison, the JavaScript code from the above link is also pasted here,
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; }; }
Following is the equivalent C# code,
class Program { class Container { // delegates delegate bool JsPrivateDelegate(); public delegate dynamic ServiceDelegate(); // constructor public Container(dynamic param) { var secret = 3; JsPrivateDelegate dec = delegate() { if (secret <= 0) return false; secret--; return true; }; Member = param; Service = () => dec() ? Member : null; } public dynamic Member { get; private set; } // public property public ServiceDelegate Service { get; private set; } // public 'method' } static void Main(string[] args) { var c = new Container("haha"); dynamic s; do { s = c.Service(); // consumes the service Console.WriteLine("{0}", s ?? "<null>"); } while (s != null); } }
Note the main point is make private members local variables as long as possible since they are accessible from the closure which C# fully supports. However as a strong-typed language, C# can't get rid of the delegate definition and the local variable definition needs to be in order within a method ('secret' has to come before 'dec').