String Split functionality-internally how does it works

[connect_fc]

Hi Gurus,

I want to write a function to split a string without using the c#'s split function..
Write our own split string function..
can anybody help me in that regards..

[Mutant_Fruit]

Generally speaking when your college gives you an assigment you're supposed to do it yourself as then you'll actually learn. If someone just hands you the solution you learn nothing.

[HanneSThEGreaT]

Hi Gurus,

I want to write a function to split a string without using the c#'s split function..
Write our own split string function..
can anybody help me in that regards..

Why do you want to reinvent the wheel??

[Pickels]

It assumes non-null input.

static string[] SplitString(string str, char[] seperator)
        {
            if (str == string.Empty)
            {
                return new string[] { str };
            }

            List<char> head = new List<char>();
            List<char> tail = new List<char>();
            bool flag = false;
            for (int i = 0; i < str.Length; i++)
            {
                if (!flag)
                {
                    if (seperator.Contains(str[i]))
                    {
                        flag = true;
                    }
                    else
                    {
                        head.Add(str[i]);
                    }
                }
                else
                {
                    tail.Add(str[i]);
                }
            }

            if (!flag && tail.Count == 0)
            {
                return new string[] { str };
            }

            List<string> items = new List<string>();
            items.Add(new string(head.ToArray()));
            foreach (string item in SplitString(new string(tail.ToArray()), seperator))
            {
                items.Add(item);
            }

            return items.ToArray();
        }

[BigEd781]

Pickels, though you are trying to be helpful, it seems pretty obvious that the OP has been given an assignment in school to write a string split function without using the built in method. So, you have essentially just done his homework for him, which is not something we like to do.

[eclipsed4utoo]

A simple look into the String class using Reflector would have given the answer.

[HanneSThEGreaT]

.................. And, just like that.......... The wheel is reinvented.

Why oh why do teachers want their students to do this is totally beyond me. And, I'm a trainer as well, and I'd rather jump off a bridge before giving any student this type of worthless assignment!!

[BigEd781]

Well, I would argue that it helps people to understand how the magic actually works. You can understand the performance characteristics, where the bottlenecks are, etc. You will likely never implement a hash table from scratch in your career, but it can sometimes be very helpful to understand how they work. Joel Spoelsky said it best in his now famous article, The Law of Leaky Abstractions

As for the OP, I don't think that he is going to get any of these benefits as he only seems concerned with someone providing an answer, not with learning at all.

[HanneSThEGreaT]

I see your point. But I'd argue that teachers aren't thinking properly anymore, perhaps I'm just old fashioned, but I'd rather jump off a bridge before asking my students to reinvent the wheel. I also like to know how things work, but why try to figure out a workaround for something that works 100% ?

OK, perhaps I'm just old & old fashioned LOL!

[BigEd781]

I think that you are just more practical. This kind of thing will not help 90% of the programmers out there. However, many programmers out there are cargo cultists and don't really know what they are doing. Sure, they may be able to get a website up and running, but ask them to do anymore than that, ask them to debug a performance bottleneck (that may reside in their non-public API, eeek!), and they will fail.

I never graduated to college, so anything I say can be taken with a grain of salt. I quit college after I realized that they take an entire semester (and a lot of my $$$) to teach me what I can teach myself using Google in about 2 weeks.

[[email protected]]

I disagree,

I see many students that come that can not do anything if Microsoft does not give them a method for it, and with a straight face expect me to hire them. Ummm if there was a method that did that, I would not need to hire you, I would just call it myself....

I will even go a step further and state that you can not really understand how to use C Sharp unless you have a very good understanding on pointers and how dynamic memory allocation is really done. Sadly too many just pass by all that in one paragrah which pretty much reads "the garbage collector takes care of it for you". I have seen to many C Sharp apps with the impossible "memory leak" to ever believe that nonesense.

Long winded way of saying that although kids these days should definatly learn to use the tools that they are given today since they increase production so much, they should also understand them.

[Mutant_Fruit]

.................. And, just like that.......... The wheel is reinvented.

Why oh why do teachers want their students to do this is totally beyond me. And, I'm a trainer as well, and I'd rather jump off a bridge before giving any student this type of worthless assignment!!

I'd rather jump off a bridge before I *don't* make students do this kind of assignment. The OP is exactly why I'd give the assignment. He couldn't figure out the wheel. If he can't figure out what you so correctly imply is a trivial and useless task, how the hell could he figure out something more complex like a lockfree threadsafe queue structure?

[HanneSThEGreaT]

Maybe I should change my way of thinking. I see all your valid points you make.

I think the whole point I have succeeded in making throughout this thread, is that I'm old fashioned

Hannes

[BigEd781]

Well, it's going to come down to the person too. We like programming, we like CS. Therefore we will go above and beyond to learn how stuff works because it drives us. For many though this is not the case and they will do the bare minimum needed to get by. Assignments like these at least forces them to think about this stuff a little. When they are running an IndexOf in a tight loop on a huge document maybe they will know where the problem lies