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Comments:
<0> k
<1> The other day I saw some graffiti talking about something like that.
<1> I won't say what it read because it's a bit too offensive if there's any navy or marine corps people here.
<0> just day it man, well i'm not from tha us but i don't think anyone would disagree
<0> it's just a statement from somebody anuyway don't worry about it
<1> This is an army/air force base for the most part. There are few sailors and marines.
<1> here
<2> hey, semi-new guy to c++... could anyone explain the use of pointers? they just seem troublesome to me
<3> abooga
<3> Static memory has to be allocated at compile time
<3> If you're tracking players in an online game
<3> And one more player joins
<3> If you only allocated 20 player slots at compile time, you can't account for him now.
<1> abooga303: Try google. There are plenty of sites that explain this type of things. Not to mention books.
<3> Or, a more practical example
<3> If you want the user to input a string
<3> You don't know how long it will be
<3> So if they need to store an entire file's contents in that string
<3> You'd better have made it a huge string at compile time, thus being very wasteful and inefficient
<2> ah, thanks for the answer JBlitzen
<3> The better approach is to dynamically allocate the amount of memory you need, when you need it, if it can't be foreseen.
<3> And the only way to dynamically allocate memory is to use "new" or "free".
<3> Both of which return pointers
<3> So, there you go.
<1> free?
<2> thank you =)
<3> er
<3> malloc
<2> but unfortunately =/ this means I have to learn pointers
<3> :D
<3> Pointers are real easy.
<3> Don't let people tell you they're complex.
<4> it's pretty basic stuff
<3> Think of them like a chess piece.
<3> It's real easy to figure out how it behaves
<1> True. Some texts scare people away from pointers and so people read too much into them when it's a simple concept.
<3> And, 40 years later, you might have some inkling as to how to use it well
<3> Yeah
<3> Don't overthink pointers. They are exactly what they call themselves.
<0> it's just a statement from somebody anuyway don't worry about it
<4> google object oriented programming
<4> it's very useful
<3> That actually wouldn't be useful at all in understanding pointers
<0> wrong window sorry
<2> I know the basics, I can understan the oob concept.
<3> er
<2> it's just pointers are a bit scary =/
<2> I dunno why
<2> *shrugs
<1> Whatever happend to the large trout?
<3> Figure out why linked lists work the way they work
<3> Then figure out how they work
<3> And you'll understand 90% of what you need to know about pointers
<2> ok
<4> JBlitzen that was hjow i learned about it anyways
<4> practical use of them
<4> pointers that is
<0> i meant to say: Jbilzen: nicely said
<3> The other 10% is dealing with dynamically allocated arrays
<0> sorry Blitzen
<3> But really, that's just a matter of using []'s here and there, the same principles apply.
<2> just as my two cents, I was running thru the tutorials on cplusplus.com
<2> taking about 2 per day
<2> I slowed down since then
<2> seeing pointers, that is
<3> Don't be too intimidated by pointers
<3> They're exactly what they call themselves.
<2> heh I go tthat much =)
<3> They're just a special data type that stores a memory address.
<3> Just like a postal address.
<3> Really, the best example is exactly what they are.
<3> int x = 5;
<3> That's an integer data type stored in a static memory slot big enough to hold an int, currently occupied by the data 5
<3> int *p = &x;
<3> That's a pointer data type stored in a static memory slot big enough to hold a pointer, currently occupied by the memory address of x
<3> cout << *p;
<3> Spits out the dereferenced (what-its-contents-point-at rather than its-contents) value of p
<3> In this case, 5
<3> Easy
<2> yes yes
<2> I could understand that
<2> I just didn't really see the practical use..
<3> It's all over the place
<2> and kinda had the thought in my mind that they weren't needed, but I learned otherwise from you =)
<5> yeah, now try to use em without leaving any edge cases that do bad things and you are ahead of the game ;)
<3> Every time you add an auction to ebay, you think they statically allocated memory for it four years ago?
<3> Now, in a sense, they don't dynamically allocate it either.
<3> But databases work much like dynamic memory works.
<3> You store data in a file, with some sort of address to find it, and you use the address all over
<3> That way, the order of the actual data doesn't matter
<5> except uber more safe for concurrent operations
<3> File systems are made the same way
<3> Yeah
<3> But the fundamentals are all there
<3> In fact, your file system is probably a great analogy of your program's memory space.
<3> You have some files which are just documents, whatever
<3> And you have other files which might reference those documents
<3> Shortcuts
<3> A pointer is just a shortcut
<4> very good example
<5> speaking of file systems... is it just me, or doesn't it **** that NTFS and other win file systems have no way to lock files for exclusive access
<6> pointing is what people do to JBlitzen
<6> shortly followed by "what a freak!"
<3> Pointing is how khan dances
<3> http://images-eu.amazon.com/images/P/B00006FN01.03.LZZZZZZZ.jpg
<2> hahahah
<6> you look horrible in white
<2> oh man
<3> I know, khan, but really, your red dress just makes my suit look bad
<3> It's the comparison that does it
<6> perhaps you should have bought me something nicer
<2> hmm, I can see how pointers would make it easy in the file system sence, as in user interaction with the program
<1> My parents were having the same argument the day they got married.
<3> You didn't deserve nicer
<2> I just still don't see the use in it in the program itself... I don't think I understand the static vs dynamic stuff yet.
<2> I'll probably learn it later though
<2> thanks alot =D
<3> abooga, file systems work on the basis of file pointers, actually.
<3> When you add a file to your system, then open windows explorer, it doesn't search every bit on your hard drive to generate a list of files
<3> It stores an index of file pointers that it can easily manipulate
<6> once you understand about how the actual hardware works, pointer support in a potential system level programming language makes sense
<3> And what that enables you to do is add and delete and move files very easily
<3> Dynamically, as many or as few as you want
<3> Whenever you want
<2> i see
<3> You aren't limited to some statically allocated array of 64 files
<3> And you can never create more than that
<3> Obviously that wouldn't make any sense whatsoever, it'd be like thinking of khan as straight.
<6> when in fact i'm a god
<3> And doing it dynamically without pointers would require windows explorer constantly searching your hard drive to see what the file structure looks like
<3> Which would be equally stupid
<0> peterhu: :) don't forget you are my demi god
<0> lol
<3> demi gaey
<1> demi actually means gay in spanish
<0> woohoo
<6> that would be JBlitzen stupid, actually
<7> clsk: Still here?
<0> clsk: seems you have a bit of a projetion problem, anyway i thought this channel was about c++
<3> Gowyl, peterhu is khan, and he's gay
<3> So we're just having fun at his expense
<0> ow k, didn't knox
<0> w
<8> hmmmm
<8> i have a math/c++ problem which i can't wrap my sad little head around
<8> I'm working on a genetic algorithm thingie... and I want to use roulette selection... but I can't figure out how i would go about ordering the list of fitness val... hell i don't even think i'm thinking about it right
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