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The beginner programming thread

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Posts

  • AndorienAndorien Registered User
    edited November 2007
    MKR wrote: »
    Andorien wrote: »
    Andorien wrote: »
    MKR wrote: »
    Hey, I like this thread.

    I have dev-c++ downloaded. I really don't know how it works and have some introduction to programming guides I plan on reading. But since I haven't even gotten my feet wet, is that a good place to start (I want to eventually make games)?

    Dev-C++ hasn't seen an update in years. :P

    http://forums.codeblocks.org/index.php?board=20.0

    Indeed. Code::Blocks is pretty much the heir to Dev-C++. Hell, it even supports Dev-C++ project files!

    Sweet. Thanks guys.

    You should be aware that CodeBlocks doesn't actually provide its own compiler, it's JUST an IDE. However, if you have Dev-C++ installed, it should pick up the compiler it has and use it.

    Also, if you like there's always Visual C++ .Net 2005 Express, which is free from MS with a valid version of Windows. I personally don't like it (though I DO like the C# IDE, and I think it's strange that it's so much better) and use .Net 2003 which I got through my school, but it's adequate and beggars can be choosers.

    Switching gears, here's a little program I made in C# as part of Gamedev.net's C# workshop.
    Program
    Source File 1
    Source File 2

    Why would you be using .NET 2003? It's free.

    Go download 2005, or 2008 if you feel like being a lab rat.

    I know it's free. But see, here's the thing, I just don't like how C++ 2005 Express operates, while 2003 doesn't piss me off near as bad. C# 2005 is fine. Also, my version of 2003 is the standard edition, which means I get cool things with it like the GUI designer, which is pretty handy when dealing with Win32.

  • MKRMKR Registered User regular
    edited November 2007
    Andorien wrote: »
    MKR wrote: »
    Andorien wrote: »
    Andorien wrote: »
    MKR wrote: »
    Hey, I like this thread.

    I have dev-c++ downloaded. I really don't know how it works and have some introduction to programming guides I plan on reading. But since I haven't even gotten my feet wet, is that a good place to start (I want to eventually make games)?

    Dev-C++ hasn't seen an update in years. :P

    http://forums.codeblocks.org/index.php?board=20.0

    Indeed. Code::Blocks is pretty much the heir to Dev-C++. Hell, it even supports Dev-C++ project files!

    Sweet. Thanks guys.

    You should be aware that CodeBlocks doesn't actually provide its own compiler, it's JUST an IDE. However, if you have Dev-C++ installed, it should pick up the compiler it has and use it.

    Also, if you like there's always Visual C++ .Net 2005 Express, which is free from MS with a valid version of Windows. I personally don't like it (though I DO like the C# IDE, and I think it's strange that it's so much better) and use .Net 2003 which I got through my school, but it's adequate and beggars can be choosers.

    Switching gears, here's a little program I made in C# as part of Gamedev.net's C# workshop.
    Program
    Source File 1
    Source File 2

    Why would you be using .NET 2003? It's free.

    Go download 2005, or 2008 if you feel like being a lab rat.

    I know it's free. But see, here's the thing, I just don't like how C++ 2005 Express operates, while 2003 doesn't piss me off near as bad. C# 2005 is fine. Also, my version of 2003 is the standard edition, which means I get cool things with it like the GUI designer, which is pretty handy when dealing with Win32.

    VC++.net 2005 express comes with a GUI designer as far as I know. All the other expresses do, so it seems logical.

  • jackaljackal Registered User regular
    edited November 2007
    Andorien wrote: »
    MKR wrote: »
    Andorien wrote: »
    Andorien wrote: »
    MKR wrote: »
    Hey, I like this thread.

    I have dev-c++ downloaded. I really don't know how it works and have some introduction to programming guides I plan on reading. But since I haven't even gotten my feet wet, is that a good place to start (I want to eventually make games)?

    Dev-C++ hasn't seen an update in years. :P

    http://forums.codeblocks.org/index.php?board=20.0

    Indeed. Code::Blocks is pretty much the heir to Dev-C++. Hell, it even supports Dev-C++ project files!

    Sweet. Thanks guys.

    You should be aware that CodeBlocks doesn't actually provide its own compiler, it's JUST an IDE. However, if you have Dev-C++ installed, it should pick up the compiler it has and use it.

    Also, if you like there's always Visual C++ .Net 2005 Express, which is free from MS with a valid version of Windows. I personally don't like it (though I DO like the C# IDE, and I think it's strange that it's so much better) and use .Net 2003 which I got through my school, but it's adequate and beggars can be choosers.

    Switching gears, here's a little program I made in C# as part of Gamedev.net's C# workshop.
    Program
    Source File 1
    Source File 2

    Why would you be using .NET 2003? It's free.

    Go download 2005, or 2008 if you feel like being a lab rat.

    I know it's free. But see, here's the thing, I just don't like how C++ 2005 Express operates, while 2003 doesn't piss me off near as bad. C# 2005 is fine. Also, my version of 2003 is the standard edition, which means I get cool things with it like the GUI designer, which is pretty handy when dealing with Win32.

    What do you mean by "GUI designer?" Express Edition has basically the same visual form designer that other editions have.

    I use Visual Studios 2003 Enterprise Developer at work and the various Express Editions at home. There aren't many times that I run into things that I need that are missing. Add-ons and conditional break points would be nice. The express editions don't have as many project types, but usually that just means you have to go into options and change a setting or write a line or two of code to get the same effect. It is worth it to get generics and anonymous delegates and LINQ and whatever that feature is called where you create a static method that takes an instance of some type and some other arguments, and then allows you to call it as if it were an instance method of that type that you passed in.

    [edit]
    Crap, you are talking about C++ and I am talking about C#. C++ is the only Express Edition I haven't installed. Several of the CS courses I took used C++, but damn I wouldn't want to use it day to day. If you know what you are doing in C# you can usually get >90% of the performance for a fraction of the effort. I say usually because a C# program could never get anywhere near 90% of the performance of FFTW, but that is what P/Invoke is for. Here is a good example.

  • AndorienAndorien Registered User
    edited November 2007
    MKR wrote: »
    Andorien wrote: »
    MKR wrote: »
    Andorien wrote: »
    Andorien wrote: »
    MKR wrote: »
    Hey, I like this thread.

    I have dev-c++ downloaded. I really don't know how it works and have some introduction to programming guides I plan on reading. But since I haven't even gotten my feet wet, is that a good place to start (I want to eventually make games)?

    Dev-C++ hasn't seen an update in years. :P

    http://forums.codeblocks.org/index.php?board=20.0

    Indeed. Code::Blocks is pretty much the heir to Dev-C++. Hell, it even supports Dev-C++ project files!

    Sweet. Thanks guys.

    You should be aware that CodeBlocks doesn't actually provide its own compiler, it's JUST an IDE. However, if you have Dev-C++ installed, it should pick up the compiler it has and use it.

    Also, if you like there's always Visual C++ .Net 2005 Express, which is free from MS with a valid version of Windows. I personally don't like it (though I DO like the C# IDE, and I think it's strange that it's so much better) and use .Net 2003 which I got through my school, but it's adequate and beggars can be choosers.

    Switching gears, here's a little program I made in C# as part of Gamedev.net's C# workshop.
    Program
    Source File 1
    Source File 2

    Why would you be using .NET 2003? It's free.

    Go download 2005, or 2008 if you feel like being a lab rat.

    I know it's free. But see, here's the thing, I just don't like how C++ 2005 Express operates, while 2003 doesn't piss me off near as bad. C# 2005 is fine. Also, my version of 2003 is the standard edition, which means I get cool things with it like the GUI designer, which is pretty handy when dealing with Win32.

    VC++.net 2005 express comes with a GUI designer as far as I know. All the other expresses do, so it seems logical.

    They come with a designer for Windows Forms, but not Win32, and I'm pretty sure C++ comes with neither. Even if it did have Forms, if I were using Forms, I'd be in C# anyway.

    Added: I should note that it's actually not mostly a matter of features. Fact is, I rarely use Win32 anyway. There's just something in the feel of it that annoys me, and is only present in VC++.net 2005. VC#.net 2005 doesn't suffer from this oddly enough.

    Added again: just tried the 2008 beta, as it occured to me that I hadn't messed with it yet. Same problems, though I appreciate them loading it up with Win32 stuff on install, rather than having to install other stuff as well as modifying the template files to get first class support going. Still no designer though.

    jackal: Ah, yeah, easy mistake to make. I actually really like the C# express edition, I think it works really well. What I hate the most about the C++ version is the build output window. It doesn't make it easy to find errors in that mass of output at all. I don't understand why they did it like they did- the C# version is great, and is identical to the 2003 editor. It confuses me greatly.

    Also, I usually code in C#, but often times C++ is needed when working with some specific API that doesn't have .Net bindings. I work in C# when I can, but C++ will always always get the job done.

  • LoneIgadzraLoneIgadzra Registered User regular
    edited November 2007
    Here's a good beginner question: How the hell can I get something like a C array in Python?

    Lists are cool and all, but not when I just need a mass of data of a fixed size that has to be accessed very quickly and is also mutable (unlike a tuple).

    Specifically, my roguelike calls for a ton of 2D arrays. I have a 2D array of tiles in the current map. My display class needs an array of tile-to-screen mappings to avoid doing lots of repeated multiplication to place tiles on the right pixels (actually I suppose that wouldn't be much faster, if at all, but I thought of this idea and dammit it seems like a good one). I need to iterate through these with "for" loops. If Python has an equivalent way of implementing this kind of thing that's not horribly inefficient, I haven't found it.

    Also, I've looked at Numeric some, and I don't need arrays of numbers - I need arrays of objects.

  • sonictksonictk Registered User regular
    edited November 2007
    Just curious: why is it that every C++ IDE I see recommended is either MS VS/VC++ or Dev C++, and no one seems to like the Eclipse project? Granted I'm no programmer, but I've tried using the IDE before to code a few simple test programs and it seems similar to VC++ in a lot of aspects.

  • AndorienAndorien Registered User
    edited November 2007
    sonictk wrote: »
    Just curious: why is it that every C++ IDE I see recommended is either MS VS/VC++ or Dev C++, and no one seems to like the Eclipse project? Granted I'm no programmer, but I've tried using the IDE before to code a few simple test programs and it seems similar to VC++ in a lot of aspects.

    As far as I know, it's because C++ isn't actually supported out of the box, and relies on a plugin that's not actually done yet.

    However, whenever someone breaths Java, Eclipse is always shouted pretty loudly.

  • MKRMKR Registered User regular
    edited November 2007
    sonictk wrote: »
    Just curious: why is it that every C++ IDE I see recommended is either MS VS/VC++ or Dev C++, and no one seems to like the Eclipse project? Granted I'm no programmer, but I've tried using the IDE before to code a few simple test programs and it seems similar to VC++ in a lot of aspects.

    The same reason people don't seem to like Blender or The GIMP. They're excellent programs with many strengths, but there is a minor learning curve on the interface.

    I didn't like Eclipse's interface, but that was a first impression, and I haven't had any incentive to try it since Code::Blocks works for me. :)

  • JaninJanin Registered User
    edited November 2007
    Here's a good beginner question: How the hell can I get something like a C array in Python?

    Lists are cool and all, but not when I just need a mass of data of a fixed size that has to be accessed very quickly and is also mutable (unlike a tuple).

    Specifically, my roguelike calls for a ton of 2D arrays. I have a 2D array of tiles in the current map. My display class needs an array of tile-to-screen mappings to avoid doing lots of repeated multiplication to place tiles on the right pixels (actually I suppose that wouldn't be much faster, if at all, but I thought of this idea and dammit it seems like a good one). I need to iterate through these with "for" loops. If Python has an equivalent way of implementing this kind of thing that's not horribly inefficient, I haven't found it.

    Also, I've looked at Numeric some, and I don't need arrays of numbers - I need arrays of objects.

    You could try using list comprehensions, I've found those to be faster than for loops in general. However, to get near-C performance in Python you'll want to take a look at a library like Pyrex.

    However, the speed benefit of moving to compiled modules in C is likely to be much less than what you could gain by simply using a more efficient algorithm.

    [SIGPIC][/SIGPIC]
  • ChewyWafflesChewyWaffles Registered User
    edited November 2007
    MKR wrote: »
    sonictk wrote: »
    Just curious: why is it that every C++ IDE I see recommended is either MS VS/VC++ or Dev C++, and no one seems to like the Eclipse project? Granted I'm no programmer, but I've tried using the IDE before to code a few simple test programs and it seems similar to VC++ in a lot of aspects.

    The same reason people don't seem to like Blender or The GIMP. They're excellent programs with many strengths, but there is a minor learning curve on the interface.

    I didn't like Eclipse's interface, but that was a first impression, and I haven't had any incentive to try it since Code::Blocks works for me. :)

    Interesting. Code::Blocks handles Java or does Eclipse handle C/C++? Either way, color me surprised, because I thought the former was mostly for C/C++ and the latter was Java. I'm a NetBeans guy, myself.


    Wow, that last sentence makes me sound like a fairy.

    mwf2sig.jpg
  • JaninJanin Registered User
    edited November 2007
    Interesting. Code::Blocks handles Java or does Eclipse handle C/C++? Either way, color me surprised, because I thought the former was mostly for C/C++ and the latter was Java. I'm a NetBeans guy, myself.


    Wow, that last sentence makes me sound like a fairy.

    Eclipse has support for C/C++ through CDT. I learned how to program in Eclipse, but was never very fond of it. I stopped using it when it began to take longer to start up than to compile my applications.

    [SIGPIC][/SIGPIC]
  • LindenLinden Registered User regular
    edited November 2007
    Janin wrote: »
    Eclipse has support for C/C++ through CDT. I learned how to program in Eclipse, but was never very fond of it. I stopped using it when it began to take longer to start up than to compile my applications.

    Eclipse supports a surprising amount. I haven't used it much, but it seems a real demonstration of the power of extensibility. Nothing like Emacs (a text editor that can do email?), but still impressive.

    And compiling compilers really sucks – as a notice to any Haskell users reading this for whatever reason, GHC 6.8.1 is now available. Of course, I couldn't get at a binary version, so I had a five-hour compilation on my hands. Which was truly wonderful.

    What if this weren't a rhetorical question?
  • LoneIgadzraLoneIgadzra Registered User regular
    edited November 2007
    Janin wrote: »
    Here's a good beginner question: How the hell can I get something like a C array in Python?

    Lists are cool and all, but not when I just need a mass of data of a fixed size that has to be accessed very quickly and is also mutable (unlike a tuple).

    Specifically, my roguelike calls for a ton of 2D arrays. I have a 2D array of tiles in the current map. My display class needs an array of tile-to-screen mappings to avoid doing lots of repeated multiplication to place tiles on the right pixels (actually I suppose that wouldn't be much faster, if at all, but I thought of this idea and dammit it seems like a good one). I need to iterate through these with "for" loops. If Python has an equivalent way of implementing this kind of thing that's not horribly inefficient, I haven't found it.

    Also, I've looked at Numeric some, and I don't need arrays of numbers - I need arrays of objects.

    You could try using list comprehensions, I've found those to be faster than for loops in general. However, to get near-C performance in Python you'll want to take a look at a library like Pyrex.

    However, the speed benefit of moving to compiled modules in C is likely to be much less than what you could gain by simply using a more efficient algorithm.

    In what context would I use list comprehensions though? My problem is not with generating or altering lists, it's with accessing them quickly. For example, my "MapView" class first decides which ranges of tiles in the array of map data will be visible, and then iterates through all the visible tiles, blitting their sprites to locations specified in a screen mapping array. At the moment, the speed of this is perfectly acceptable on my MacBook Pro, so I'm calling it good for now, but I'm concerned that it may be an issue.

  • LewishamLewisham Registered User regular
    edited November 2007
    As you are still learning Lone, I just wouldn't concern yourself with it. The important thing is that it works.

    1. Make something that works.
    2. Make it work fast.

    Do number 1 throughout the whole project first. Worry about the other stuff later; that's why we use abstraction in object-orientated programming; you get to screw to your heart's content later on, and not break stuff (as long as you pay attention to the API).

  • Recoil42Recoil42 Registered User
    edited November 2007
    So I'm too lazy to make an "The Intermediate programming thread" but anyways, this'll suffice.

    So I'm messing around with PHP and SQL/MySQL, and well... there's something bugging me. Do you *really* put the username/password to the SQL database in every PHP file that wants to access it? Doesn't that seem... just a little insecure to anyone else?

    I mean, if there's ever an apache glitch, and a user gets the raw PHP file... all your data is compromised. No?

  • JaninJanin Registered User
    edited November 2007
    Oh, in that case you might want to use map (). The basic rules when it comes to loop speed is that for loops are slow, map is fast, and list comprehensions are fastest. This holds true even if you just throw away the calculated values. The Python wiki has some more information on loop speed: PerformanceTips: Loops, PythonSpeed, Python Patterns - An Optimization Anecdote.

    As a dynamic language, ways to increase performance in Python might not be obvious. I wouldn't worry about it at all until it starts affecting your framerate.

    [SIGPIC][/SIGPIC]
  • JaninJanin Registered User
    edited November 2007
    Recoil42 wrote: »
    So I'm too lazy to make an "The Intermediate programming thread" but anyways, this'll suffice.

    So I'm messing around with PHP and SQL/MySQL, and well... there's something bugging me. Do you *really* put the username/password to the SQL database in every PHP file that wants to access it? Doesn't that seem... just a little insecure to anyone else?

    I mean, if there's ever an apache glitch, and a user gets the raw PHP file... all your data is compromised. No?

    Put connection details in an external configuration file, then create a PHP function to load + parse the file, and return a database connection based on the data contained. If you put the configuration file outside the webroot, a proper webserver won't display it.

    [SIGPIC][/SIGPIC]
  • Recoil42Recoil42 Registered User
    edited November 2007
    Janin wrote: »
    Recoil42 wrote: »
    So I'm too lazy to make an "The Intermediate programming thread" but anyways, this'll suffice.

    So I'm messing around with PHP and SQL/MySQL, and well... there's something bugging me. Do you *really* put the username/password to the SQL database in every PHP file that wants to access it? Doesn't that seem... just a little insecure to anyone else?

    I mean, if there's ever an apache glitch, and a user gets the raw PHP file... all your data is compromised. No?

    Put connection details in an external configuration file, then create a PHP function to load + parse the file, and return a database connection based on the data contained. If you put the configuration file outside the webroot, a proper webserver won't display it.

    Ewww.. really? Is that what "everyone else" does, too?

  • LewishamLewisham Registered User regular
    edited November 2007
    That seems reasonable Recoil. Putting the database password in a file only readable by the web server somewhere that it won't display is pretty normal, it's certainly how my workplace does stuff in Perl.

  • Recoil42Recoil42 Registered User
    edited November 2007
    Reasonable, yes, but still a lot of code for something so trivial. I found another idea/method in the comments section of the PHP online docs that is a lot simpler, though not as flexible: Rather than storing the username/pass in a plain text file to be parsed, as above; instead store them in a PHP file.

    That way, rather than having to load and parse the text file, you just include the PHP file:

    http://www.php.net/manual/en/function.mysql-connect.php#73983
    <?php
        $g_link = false;
       
        function GetMyConnection()
        {
            global $g_link;
            if( $g_link )
                return $g_link;
            $g_link = mysql_connect( 'host.name', 'user', 'password') or die('Could not connect to server.' );
            mysql_select_db('database_name', $g_link) or die('Could not select database.');
            return $g_link;
        }
       
        function CleanUpDB()
        {
            global $g_link;
            if( $g_link != false )
                mysql_close($g_link);
            $g_link = false;
        }
       
    ?>
    

    Simply include your connnection.php file in your script and anywhere you use the mysql_query() function include a call to the GetMyConnection() function.
    <?php
        $res = mysql_query("SELECT ...", GetMyConnection() );
    ?>
    

  • Shazkar ShadowstormShazkar Shadowstorm Registered User regular
    edited November 2007
    So as part of one assignment I need to remove the "magic numbers" from a bit code. But they are all just different numbers to scale down a given input to make a pretty picture of a car, sometimes by 6, or 2/3 or 3... should I just make final static variables called like... SCALE_DOWN_BY_SIX, SCALE_DOWN_BY_TWO_THIRDS, SCALE_DOWN_BY_THREE, and so on, or is there a better way I should be naming these/going about with this?

    Damn this OOD&P class and its horrible teacher.

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  • GanluanGanluan Registered User regular
    edited November 2007
    Recoil42 wrote: »
    Janin wrote: »
    Recoil42 wrote: »
    So I'm too lazy to make an "The Intermediate programming thread" but anyways, this'll suffice.

    So I'm messing around with PHP and SQL/MySQL, and well... there's something bugging me. Do you *really* put the username/password to the SQL database in every PHP file that wants to access it? Doesn't that seem... just a little insecure to anyone else?

    I mean, if there's ever an apache glitch, and a user gets the raw PHP file... all your data is compromised. No?

    Put connection details in an external configuration file, then create a PHP function to load + parse the file, and return a database connection based on the data contained. If you put the configuration file outside the webroot, a proper webserver won't display it.

    Ewww.. really? Is that what "everyone else" does, too?

    I'm not familiar with PHP specifically, but for ASP .NET you almost always store your connection strings in a Web.Config file, similar to what Janin is talking about. Although in ASP, the Web.Config consists of key/value pairs in a very fast hashtable, so it's extremely easy to read from.

  • GanluanGanluan Registered User regular
    edited November 2007
    So as part of one assignment I need to remove the "magic numbers" from a bit code. But they are all just different numbers to scale down a given input to make a pretty picture of a car, sometimes by 6, or 2/3 or 3... should I just make final static variables called like... SCALE_DOWN_BY_SIX, SCALE_DOWN_BY_TWO_THIRDS, SCALE_DOWN_BY_THREE, and so on, or is there a better way I should be naming these/going about with this?

    Damn this OOD&P class and its horrible teacher.

    Something similar to what you're doing would be fine. The main idea behind removing all magic numbers and using constants instead is that your code is basically documenting itself.

    scale * 6.37894 doesn't make much sense compared to scale * SCALE_FACTOR_SIX.

  • Shazkar ShadowstormShazkar Shadowstorm Registered User regular
    edited November 2007
    Ah, that makes sense. The assignment said to make it more self documenting as well, so I guess this is a part of it.

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  • mastmanmastman Registered User regular
    edited November 2007
    I imagine you can find some PHP libraries already written to do standard stuff like read connectino properties from a file and create a connection for you.

    ByalIX8.png
  • MaximilianMaximilian Registered User
    edited November 2007
    So as part of one assignment I need to remove the "magic numbers" from a bit code. But they are all just different numbers to scale down a given input to make a pretty picture of a car, sometimes by 6, or 2/3 or 3... should I just make final static variables called like... SCALE_DOWN_BY_SIX, SCALE_DOWN_BY_TWO_THIRDS, SCALE_DOWN_BY_THREE, and so on, or is there a better way I should be naming these/going about with this?

    Damn this OOD&P class and its horrible teacher.

    You need to give your constants names that express the meaning of them and not the value. I hope I can explain this:

    In this case it mostly depends on how the value is chosen. If, say, these values can be chosen by the user (in a combo box or something), I would probably name them something like SCALE_LEVEL_1, SCALE_LEVEL_2 and so on (or better yet, create a lookup array). Like this, if the options for the user change you can just change the value of a certain SCALE_LEVEL.

    If the used value depends on a different thing you need to give it a different name. Perhaps it depends on current connection speed to a server, then you should name them something like SCALE_LEVEL_FAST_CONN, SCALE_LEVEL_SLOW_CONN and so on.

    If you do it like this, and somebody decides that for super fast connections you don't have to scale anything at all, you just need to change the value of SCALE_LEVEL_SUPER_FAST_CON to "1". If you would have called it SCALE_DOWN_BY_TWO, then for clarity's sake you would also have to change the name to DONT_SCALE (or something) and all of its occurences in the code. And this is exactly what you are trying to avoid when using constants.

    Simple rule: If you need to change the name of your constant whenever its value changes than the name is bad or you just don't need a constant at all.

    Did this help?

  • Shazkar ShadowstormShazkar Shadowstorm Registered User regular
    edited November 2007
    Hm, alright, that makes sense. I'll need to look at this code thoroughly to understand what each of these numbers are doing, because as far as I can tell these constants are just arbitrary ones to make a picture of a car based on a given width input.

    EDIT: When can the Java compiler tell what the exact method that will be called before a program executes? W/regards to polymorphism. I'm trying to find it in this chapter of my textbook, but I cannot.

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  • MaximilianMaximilian Registered User
    edited November 2007
    EDIT: When can the Java compiler tell what the exact method that will be called before a program executes? W/regards to polymorphism. I'm trying to find it in this chapter of my textbook, but I cannot.

    It can't. When you call a virtual method it's decided at runtime which implementation is executed. The compiler just doesn't know. It only stores somethig like "Call method xyz on the object at this place.", and when the program executes, different methods get executed depending on the type of "the object at this place".

  • Shazkar ShadowstormShazkar Shadowstorm Registered User regular
    edited November 2007
    That's what I thought... hence why I am confused when there is a question in my book asking to name two situations where it can do just what I asked... weird. Hm. Google times...

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  • MaximilianMaximilian Registered User
    edited November 2007
    Well, if you do
    MyType foo = new MyType();
    foo.someMethod()
    

    The compiler can probably determine that someMethod of type MyType will be called and optimize the dispatching away. But from a programming perspective this doesn't matter at all.

  • mausmalonemausmalone Registered User
    edited November 2007
    Recoil42 wrote: »
    Janin wrote: »
    Recoil42 wrote: »
    So I'm too lazy to make an "The Intermediate programming thread" but anyways, this'll suffice.

    So I'm messing around with PHP and SQL/MySQL, and well... there's something bugging me. Do you *really* put the username/password to the SQL database in every PHP file that wants to access it? Doesn't that seem... just a little insecure to anyone else?

    I mean, if there's ever an apache glitch, and a user gets the raw PHP file... all your data is compromised. No?

    Put connection details in an external configuration file, then create a PHP function to load + parse the file, and return a database connection based on the data contained. If you put the configuration file outside the webroot, a proper webserver won't display it.

    Ewww.. really? Is that what "everyone else" does, too?

    I don't even put it outside the the webroot (because my hosting company won't allow it). I actually have it set variables. The variables will never display unless I actually tell them to display.
    <?PHP
    $MYSQLDBName = "db";
    $MYSQLUser = "my_username";
    $MYSQLPassword = "my_password";
    ?>
    

    This is actually pretty damned secure because even if somebody knows where your config file is the web server will never serve that up as text that they can read. The only way they'd be able to read your database username and password would be if they had file access to your server ... and then you'd have bigger problems to worry about.

    The bigger danger is from SQL injection, but as long as you realize that you can take steps to prevent it.

    266.jpg
  • JaninJanin Registered User
    edited November 2007
    mausmalone wrote: »
    Recoil42 wrote: »
    Janin wrote: »
    Recoil42 wrote: »
    So I'm too lazy to make an "The Intermediate programming thread" but anyways, this'll suffice.

    So I'm messing around with PHP and SQL/MySQL, and well... there's something bugging me. Do you *really* put the username/password to the SQL database in every PHP file that wants to access it? Doesn't that seem... just a little insecure to anyone else?

    I mean, if there's ever an apache glitch, and a user gets the raw PHP file... all your data is compromised. No?

    Put connection details in an external configuration file, then create a PHP function to load + parse the file, and return a database connection based on the data contained. If you put the configuration file outside the webroot, a proper webserver won't display it.

    Ewww.. really? Is that what "everyone else" does, too?

    I don't even put it outside the the webroot (because my hosting company won't allow it). I actually have it set variables. The variables will never display unless I actually tell them to display.
    <?PHP
    $MYSQLDBName = "db";
    $MYSQLUser = "my_username";
    $MYSQLPassword = "my_password";
    ?>
    

    This is actually pretty damned secure because even if somebody knows where your config file is the web server will never serve that up as text that they can read. The only way they'd be able to read your database username and password would be if they had file access to your server ... and then you'd have bigger problems to worry about.

    The bigger danger is from SQL injection, but as long as you realize that you can take steps to prevent it.

    He was specifically asking how to avoid compromising his password if his server was misconfigured to send PHP scipts as plain text, which your solution does not address. Get a better hosting provider.

    [SIGPIC][/SIGPIC]
  • MKRMKR Registered User regular
    edited November 2007
    Keep the config file above the web root.

  • HalibutHalibut Registered User regular
    edited November 2007
    No love for Java in this thread? I suppose a dynamic language is probably easier to learn for beginners.

    There's a language modeled after Ruby called Groovy. It's pretty cool because it has a very Ruby-like syntax (most of Ruby's core language features like dynamic typing, closures, etc...), but it runs on Java's JVM. It can also be compiled to Java .class files and then imported in any Java class (and vice versa). This allows a lot of quick prototyping opportunities where you can create an implementation of some component in Groovy and replace it later with a Java implementation if you need to.

  • JaninJanin Registered User
    edited November 2007
    Halibut wrote: »
    No love for Java in this thread? I suppose a dynamic language is probably easier to learn for beginners.

    There's a language modeled after Ruby called Groovy. It's pretty cool because it has a very Ruby-like syntax (most of Ruby's core language features like dynamic typing, closures, etc...), but it runs on Java's JVM. It can also be compiled to Java .class files and then imported in any Java class (and vice versa). This allows a lot of quick prototyping opportunities where you can create an implementation of some component in Groovy and replace it later with a Java implementation if you need to.

    There's a "Static Languages" section, but I'd rather not put too much of that stuff in the OP. I'm sure everybody in the thread would be happy to help with Java questions, but if somebody stumbles in wanting to learn the basics I'd rather they learn with an easy language.

    [SIGPIC][/SIGPIC]
  • Shazkar ShadowstormShazkar Shadowstorm Registered User regular
    edited November 2007
    Could one answer for that question I asked above be if there is no superclass of that class that contains a method with the same signature?

    Hmmm

    Exact question being this:
    In Java, a method call on an object such as x.f() is resolved when the program executes, not when it is compiled, in order to support polymorphism. Name two situations where the Java compiler can determine the exact method to be called before the program executes.

    Even if the one I mentioned is one of those... I can't think of the other..?

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  • JaninJanin Registered User
    edited November 2007
    Could one answer for that question I asked above be if there is no superclass of that class that contains a method with the same signature?

    Hmmm

    Exact question being this:
    In Java, a method call on an object such as x.f() is resolved when the program executes, not when it is compiled, in order to support polymorphism. Name two situations where the Java compiler can determine the exact method to be called before the program executes.

    Even if the one I mentioned is one of those... I can't think of the other..?

    Is it possible in Java to have non-virtual methods?

    [SIGPIC][/SIGPIC]
  • Shazkar ShadowstormShazkar Shadowstorm Registered User regular
    edited November 2007
    Hey, anyone know of any good sites for general resources on OOP?

    I need to find and define different "super" patterns, just looking up the definitions on the web, and I could find most on wikipedia or other sites, but I'm not sure how to define Fundamental patterns... the other ones are pretty simple, like a Creational pattern is obviously one that deals with the instantiation process.

    Hm. Design... what madness. Important I guess though.

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  • HalibutHalibut Registered User regular
    edited November 2007
    Janin wrote: »
    Could one answer for that question I asked above be if there is no superclass of that class that contains a method with the same signature?

    Hmmm

    Exact question being this:
    In Java, a method call on an object such as x.f() is resolved when the program executes, not when it is compiled, in order to support polymorphism. Name two situations where the Java compiler can determine the exact method to be called before the program executes.

    Even if the one I mentioned is one of those... I can't think of the other..?

    Is it possible in Java to have non-virtual methods?

    That's a good point. If a method is declared final, then no child class can override it, so if you had something like this:
    public class ParentClass{
        public final void someMethod(){ //do something}
    }
    
    Then you will get a compiler error if you try to do something like this:
    public class ChildClass extends ParentClass{
        public void someMethod(){//compiler error}
    }
    

    Another case where the compiler would know the exact class that a method is invoked for would be for static methods.

  • JaninJanin Registered User
    edited November 2007
    Hey, anyone know of any good sites for general resources on OOP?

    I need to find and define different "super" patterns, just looking up the definitions on the web, and I could find most on wikipedia or other sites, but I'm not sure how to define Fundamental patterns... the other ones are pretty simple, like a Creational pattern is obviously one that deals with the instantiation process.

    Hm. Design... what madness. Important I guess though.

    Ewww, patterns. Wiki has pages on Fundamental and Creational desgin patterns. If your library has the Gang of Four book, that would be a good reference.

    [SIGPIC][/SIGPIC]
This discussion has been closed.