PIEBALDconsult wrote:

1. A fairly pointless question. Object, but I never think about its members, I only override them when necessary -- so at most I might say ToString.

Hehe - ok ok. This is clearly a very divisive question! Despite the howls of protest around this so far I still like this as a question. Maybe I'm just evil.... ;)

PIEBALDconsult wrote:

2. Not too bad a question. I use delegates, but I don't recall ever using Invoke or BeginInvoke on them. If you want to ask about synchronous/asynchronous, then just ask.

I agree we could ask directly something along the lines of how would you run a delegate asynchronously but really its just the same question posed another way. I suspect you have used Invoke even if you don't realise it :)

PIEBALDconsult wrote:

3. I certainly couldn't fill two minutes with that, because I just don't need to know, that's the whole point of the GC.

I think this is an interesting statement. Maybe you are right and its why so many people struggle with it. I naturally assumed that since I have been asked this at every .NET interview this was a totally standard question. Maybe its specific though to the industry I'm in and the type of application we are generally developing where memory and cpu time are at a premium. Food for thought for me.

PIEBALDconsult wrote:

5. Right, they're not, but there's nothing I can do about it; all I can do is make my classes thread-safe -- when needed.

But the point is you know - a hell of a lot of candidates don't!

Translated to yearly salary that's about $150,000 which I don't think is exactly bad?

Thanks for your reply. Absolutely - there are a lot more where they came from! We have specific questions around all of the things you mention. Just to be clear though the point of my post was however not to ask for more questions but rather to ask are these unfair or unrealistic things to expect someone to know who wants $600+ a day?

Thanks - interesting points. People have commented at work on if asking about public methods on object is useful. I don't think knowing all 4 (or 5!) is necessary I agree but when to use them is absolutely imperative. If you don't know when to override Equals for example you can't have done much C# - well imho. I might rephrase this going forward. We ask about the garbage collector precisely because we want them to talk about Finalize vs Dispose and how the dispose pattern is connected to garbage collection (GC.SuppressFinalize etc). We also feel for the types of applications we use which often require a lot of memory analysis to detect memory not being freed it is imperative to know whats going on in the GC. If you'd have answered my ArrayList like that you'd come straight in for second round!! ArrayList question does indeed go two ways - one is why is List better than ArrayList. Second goes down into the threading route of what can and can't you lock on, alternatives to plain lock etc. It depends on the candidate. Yeah - I post here very rarely so apologies if this is in the wrong place!

Fair point - badly phrased in my original post. The question does specify public instance methods not class (static) methods. We don't count Finalize as you can't call it directly but I would accept that. MemberwiseClone certainly wouldn't count as thats protected not public.

Hi All I've been doing interviews for a large multi national company for a number of C# contractors to work on a greenfield winforms application. In the last month I've interviewed 28 candidates and only 6 have passed our first technical test which is a 1/2 hour telephone screening. What I'm wondering is if our basic questions are viewed by the community as not fair game. Our basic premise is that if you can't answer four out of five of these basic questions (first ten minutes of interview) there is little point in pursuing things further. 1) What is the base object in C#.NET, its public instance methods and when would you use them? - I'm astonished how few people get this. I generally forgive forgetting GetHashCode but Equals?! - only maybe 25% of people get 3 out of the 4 methods (or 5 if you count Finalize which in general we don't). 2) What is a delegate? What is the difference between delegate.Invoke and delegate.BeginInvoke? - Really asking do you know the difference between synchronous and asynchronous programming. - maybe 20% get this. 3) Give a two minute overview of how the garbage collector works? (Looking for what makes an object eligible for collection, when it runs, concept of generations, implications of having a finalizer etc) - very poor understanding out there - I've had 1 good explanation so far. 4) Explain the OO concept of polymorphism and how you can take advantage of it in C#? Why do you think Microsoft didn't make all methods virtual by default? - I.e. whats a virtual function and to understand the performance implications of them. - most get the first, nobody so far the second. 5) Is ArrayList/List a thread safe collection? If not how would you make it thread safe? - most get its not, only some really have any idea how to make it thread safe. I just don't think these are hard questions, especially given the daily rates we are offering, but maybe I'm being too hard? What do you think? Whats really strange is we're doing a lot of Java interviews for the server side of things as well and we've seen plenty of great candidates. Maybe there are just lots and lots of very poor C# candidates out there and I'm getting my fair share of them! Cheers!

modified on Friday, October 2, 2009 6:08 PM

In a new body of code I've "inherited" there is a lot of code that looks something like this (simplified somewhat):

public class A
{
private ArrayList list = new ArrayList();
private object m_lock = new object();

public A()
{
lock(m_lock)
{
list.Add("MyString");
}
}
}

Now am I going mad? That lock statement to my eye is marginally pointless. Is there ever any justification for locking on a non static, private object in a constructor? Cheers, E.

Hi All, In both my last job and my current job we have had applications that sit on (very) busy PC's which typically run anywhere between 10-20 spreadsheets in Excel, several internet explorers, market data systems etc. In both cases our C# application always runs out of handles and stops working (throws exceptions etc) with problems in the call to CreateHandle. Clearly whats happening is we are hitting the internal win32 handle limits. I know of a registry entry that I can change that will increase the limit but this at best still only stalls the problem - not fixes it. Others among you must have seen this problem so what did you do about it? Cheers, E.

No - i think you've missed the point of my original post. I know perfectly well I could do ask you suggest but that wasn't my question.

Hi Could anyone please explain to me why the following results in two mdi forms but the textbox only appearing on the second one? Clearly there is some sort of mechanism preventing me from hosting the same control on two different forms but I can't find any documentation regarding this. public Form1() { // // Required for Windows Form Designer support // InitializeComponent(); this.IsMdiContainer = true; TextBox box = new TextBox(); Form frmchild=new Form(); frmchild.MdiParent=this; frmchild.Controls.Add(box); frmchild.Show(); Form frmchild2=new Form(); frmchild2.MdiParent=this; frmchild2.Controls.Add(box); frmchild2.Show(); } Thanks in advance! Ewan.

If you have a high spec PC then I can't recommend Far Cry enough. Inovative, looks stunning, damn hard and a really different type of FPS.

I think you are slightly missing the point. Personally when I approach a problem and find a stumbling block I do the following: 1) Read the documentation. 2) If the answer isn't forthcoming (as it really isn't in this case) (oh and your answer is plain wrong btw for the standard edition) ask someone who likely has far more knowledge than I will every have on the subject. Result.... almost immediate answer (plus obligatory flaming). I've coded in c++ for many years and while I am certainly a code monkey at heart I would like to think I do amount to something ;-) . Just because I'm trying to expand my knowledge in the form of c# shouldn't mean I have to read the entire MSDN before I'm entitled to ask questions. Ewan.

Hehehe No problem. Can't say I blame you ;-) Am very new to .NET environment having done lots in VC++ 6. Can't say the transition is going well ;-) Ta Ewan.

Thanks, Not really answering the question I asked tho: How do I create it in VS.NET 2002. Not notepad? I.e. where is the setting where I tell the IDE that I want the command line compile option /t:library Thanks, Ewan.

Hi All, Could anybody point me in the right direction of how to create a class library using C#.NET 2002 standard edition? As it does not have a project template for creating a class library I am finding it difficult to find the right incantation. Any help would be appreciated? (I am assuming this is actually possible.... ;-) ) Cheers, Ewan.