From: "Dan Stevens (IAmAI)" Date: 2007-07-06T07:13:31+09:00 Subject: Calling an arbitrary method as and when an array's contents change I have a collection class that extends the Array class and I wish to have a particular method to be called whenever the contents of an instance of the class change. Can anyone advise on how I can achieve this? I'm aware that I can compare #hash with a previous saved value to determine if the contents of the instance have changed since the last time #hash was called. Therefore, if I can find a means of calling an arbitrary method or piece of code every time any method is called on the instance, I could achieve what I'm after. Can I override Object#send?