Skip to main content

Understanding Generics in C#

We have begun introducing generics into all of our code at work and I have found it difficult to understand, lots of 's and this sort of thing and when you multiply that across all of the project I have decided I need to get a grip on generics in C#.

My port of call was the Microsoft MSDN website, and that is what I am looking at now allthough I have 2 books as well, Beginning C# 2005 (Wrox Press) and C# In depth (Skeet).

My first question was what is the benefits of generics, I managed to survive without them before. Luckily one of the articles on the MSDN website answers this directly http://msdn.microsoft.com/en-gb/library/b5bx6xee.aspx

Obviously this article doesn't answer all of the questions it just addresses using list over arraylist however it is a start. What I hadn't realised was that when you use an arraylist is casts everything you add to the array into the object type which is both performance hungry and also allows you to run the chance of a run time error.

For example the website uses

System.Collections.ArrayList list = new System.Collections.ArrayList();
// Add an integer to the list.
list.Add(3);
// Add a string to the list. This will compile, but may cause an error later.
list.Add("It is raining in Redmond.");
int t = 0;
// This causes an InvalidCastException to be returned.
foreach (int x in list){ t += x;}

Here you would not want to be mixing to different types but if you used a generic list instead the error would have been flagged up immediately.


Comments

Popular posts from this blog

Making your domain less mutable

This happens regularly to me (and from my anecdotal investigation everyone involved in large / old projects). We need a new piece of functionality. I write it, it's beautiful and I win the internet. I have estimated 8 days (or 22.23 lol-points depending on how you live) and it's only taken 4 days. Ah, but then a very small; mostly ignored and very unimportant detail rears it's cruel head. You need to make it work with the code that exists already. This is normally in the form of saving to some pre-existing entities. Oh dear. You save everything through the various management / service classes that exist already and nothing works. So begins the next couple of days of horror. You find that you didn't set the work = true . Most of my woes in this area are caused by modifications at layer further down (or the stored procedure it finally ends up in) changing the object that I was trying to save or not saving part of the object because of some rule. So many errors

IIS Administration using Microsoft.Web.Administration using F#

A friend had mentioned his joy at using Powershell. I guess this is pretty cool and I don't mind Powershell. I sort of missed the boat a little with it because I haven't done any Windows Administration since I used to look after Windows Server 2000 machines (and possibly a couple of 2003). At that time I had a different arsenal to cause untold woe on my fellow colleagues....VBSCRIPT!!!! Boy could I cause trouble with that. With a combination of that, VBA and SQL I used to love creating spider webs of pure madness, once written the apps were tied together so precariously; one false move and the entire thing would explode.... anyway that's a different story. Back to the Powershell. He was using it to automate IIS (or else I heard what I wanted to so I could try and push F# onto him, who knows?). I have heard various stories of extremely large platform automation scripts being written recently (for example  .net rocks interview with Steve Evans ) and whilst they seem to be g

My home office upgrade wish list.

My home office is almost due an upgrade. I have been holding off until my youngest daughter is out of her cot as then we can finally dispatch the enormous monstrosity of a cot out from the kids bedroom and the drawers that are in my office can be banished giving me better access to my wonderful whiteboard. My other improvements will be purchasing a new, larger monitor. I currently work from a single 22ich Samsung which just doesn't cut it anymore, I did have two at some point but I can't recall what I did with it. I really enjoy using a touch screen so I think I will go for one of these 27inch Hannspree models that I have used before. I put a lot of hours in at home and whilst I have a reasonable chair I still tend to suffer with some back problems, so my next port of call will be to get a Varidesk for home. It works an absolute treat at work and just lets me switch stuff up when I feel like it. they take a reasonable amount of desk space up but I tend to leave my desk fairly