Search Results

Search found 4685 results on 188 pages for 'cpp beginner'.

Page 58/188 | < Previous Page | 54 55 56 57 58 59 60 61 62 63 64 65  | Next Page >

  • simple putStrLn in Haskell/Yampa with arrows syntax

    - by sisif
    i'm using Haskell with the Yampa FRP library which uses the arrows language extension. how can i do a simple putStrLn in a SF? mySF = proc x -> do y <- identity -< x*x putStrLn "Hello World!" ++ show y returnA -< y the arrow syntax complains about the expression not bein an arrow (of course), but even with arrows i get no output output <- identity -< putStrLn "Hello World!"

    Read the article

  • Why has to be size of dynamically-allocated array a static field?

    - by Ondrej Slinták
    I have a dummy class where I am testing arrays. I've noticed that when I want to dynamically allocate size of array at runtime, fields that indicate this size have to be static. I know I should probably use collections for this kind of code, but I'm more interested why do these fields have to be static? Is there any particular reason behind this? class Foo { private static int x; private static int y; private int[,] bar = new int[ x, y ]; public Foo( int a, int b ) { x = a; y = b; } }

    Read the article

  • JButtons re-enable themselves after being disabled

    - by Anarchist
    I have an array of JButtons which form a keypad interface. After six numbers are entered I want to disable the keypad so that no further numbers can be entered by the user. I have written the code and the buttons do disable until the mouse hovers above any of them, then the buttons seem to re-enable themselves and run actionEvents added to them. The full code is available here. Possible things that I think are wrong. There is some sort of MouseListener which is ignoring when I set button.setEnabled(false); I haven't separated attributes from the buildGUI(); correctly, I only did this anyway so that the inner class could access them. Possibly something to do with the gridLayout as disabling the buttons seems to work for my services JPanel buttons.

    Read the article

  • Problem with foreach loop and $_GET

    - by phpExe
    I have a very simple foreach loop foreach($tv as $id => $channel) { $ID = $_GET['ID']; if($ID == $id){$class = "currentt";} echo '<a href="http://www.mysite.com/tst.php?ID='.$id.'" class="'.$class.'">'.$channel.'</a><br>'; } With url query, with every click the current class repeated. How can avoid this? Thanks alot.

    Read the article

  • How did you learn to be a programming guru?

    - by Xonara
    College courses are obviously very helpful, but I hear all the time about great programmers that just "taught themselves," and I wonder how the hell they did it. Online tutorials are nice - online support, even better - but learning with nothing but online resources is difficult to say the least, and I don't know anybody that's experienced enough to help me learn. Even if I did, they probably wouldn't have the time for it. Any advice is greatly appreciated. Becoming an application/game designer is something I've wanted to achieve for a long, long time, even if I never use it for a career, and it does mean alot to me. However, I'm constantly thwarted by lack of motivation, or perhaps confidence. Though I've found some good tutorials online, sometimes I feel it just isn't enough to really get me somewhere, and my limited knowledge of computers (and any other technology) in general is hardly reassuring. I'm constantly getting the feeling that maybe it isn't "in me." Well, guess that's it. I just don't want to join the legions of aspiring techies that just gave up.

    Read the article

  • howto Debugging on PHP

    - by justjoe
    how we do basic debugging in PHP ? Can anybody share true horror story on debugging PHP application (or (even better) on PHP framework such Codeigniter and Wordpress) ? i love to hear real experience in case i have to encounter similar situation on my journey to learn PHP.

    Read the article

  • Is it a good idea for me to learn Python before C or some other Compiler language?

    - by Dream Lane
    Right now I am going through MIT's introduction to Computer Science course via OpenCourseWare. As a part of this course I am learning the Python Language. I've read a lot of things about the benefits of learning C. Before I dig any deeper into Python I wonder if I will be hindered or helped by learning Python first. Do you think that I will develop any bad habits or anything like that from Python?

    Read the article

  • Python text file processing speed issues

    - by Anonymouslemming
    Hi all, I'm having a problem with processing a largeish file in Python. All I'm doing is f = gzip.open(pathToLog, 'r') for line in f: counter = counter + 1 if (counter % 1000000 == 0): print counter f.close This takes around 10m25s just to open the file, read the lines and increment this counter. In perl, dealing with the same file and doing quite a bit more (some regular expression stuff), the whole process takes around 1m17s. Perl Code: open(LOG, "/bin/zcat $logfile |") or die "Cannot read $logfile: $!\n"; while (<LOG>) { if (m/.*\[svc-\w+\].*login result: Successful\.$/) { $_ =~ s/some regex here/$1,$2,$3,$4/; push @an_array, $_ } } close LOG; Can anyone advise what I can do to make the Python solution run at a similar speed to the Perl solution? I've tried just uncompressing the file and dealing with it using open instead of gzip.open, but that made a very small difference to the overall time.

    Read the article

  • mapping list of different types implementing same function?

    - by sisif
    I want to apply a function to every element in a list (map) but the elements may have different types but all implement the same function (here "putOut") like an interface. However I cannot create a list of this "interface" type (here "Outputable"). How do I map a list of different types implementing the same function? main :: IO () main = do map putOut lst putStrLn "end" where lst :: [Outputable] -- ERROR: Class "Outputable" used as a type lst = [(Out1 1),(Out2 1 2)] class Outputable a where putOut :: a -> IO () -- user defined: data Out1 = Out1 Int deriving (Show) data Out2 = Out2 Int deriving (Show) instance Outputable Out1 where putOut out1 = putStrLn $ show out1 instance Outputable Out2 where putOut out2 = putStrLn $ show out2 I cannot define it this way: data Out = Out1 Int | Out2 Int Int putOut Out1 = ... putOut Out2 = ... because this is a library and users should be able to extend Out with their own types

    Read the article

  • how to determine count of tag

    - by peter
    I have a bit of xml file named Sample.xml which is shown below <?xml version="1.0" encoding="ISO-8859-1"?> <countries> <country> <text>Norway</text> <value>N</value> </country> <country> <text>Sweden</text> <value>S</value> </country> <country> <text>France</text> <value>F</value> </country> <country> <text>Italy</text> <value>I</value> </country> </countries> i have button named submit(button1).If i click that button i need to display the count(PartitionName="AIX") in a text box named textBox1, means How many PartitionName="AIX" is belonging to Type="NIC" Can any one give me the c# code I did like this,,but not able to get the answaer private void button1_Click(object sender, EventArgs e) { XmlDocument doc1 = new XmlDocument(); doc1.Load(@"D:\New Folder\WindowsFormsApplication3\WindowsFormsApplication3\Sample.xml"); XmlNodeList a = doc1.GetElementsByTagName("AIX"); textBox1.Text = a.Count.ToString(); }

    Read the article

  • for line in open(filename)

    - by foosion
    I frequently see python code similar to for line in open(filename): do_something(line) When does filename get closed with this code? Would it be better to write with open(filename) as f: for line in f.readlines(): do_something(line)

    Read the article

  • WPF DataContext syntax - Convert from C# to VB

    - by hawbsl
    Currently working through a Teach Yourself WPF tutorial. Usually I can mentally convert from C# to VB without any problem but this C# syntax is unfamiliar. How is it written in VB? Private void Button_Click(object sender, RoutedEventArgs e) { ((Person)DataContext).FirstName = "blah blah" } My usual fave online converters are choking on this ... perhaps because they don't do WPF?

    Read the article

  • extract variables from an expression using javascript regexp

    - by powerboy
    For example, here is a string representing an expression: var str = 'total = sum(price * qty) * 1.09875'; I want to extract variables (i.e., 'total', 'price' and 'qty' but not 'sum' since 'sum' is a function name) from this expression. What is the regexp pattern in javascript? Variable name consists of letters, digits, or the underscore, beginning with letters or the underscore.

    Read the article

  • TB3.0.10: Messages being sent back to me

    - by punkinette64
    Hello, I don't know if this will make any sense to you; but here goes. When I send an email and I get a response, more often than not, in the 'to:' is my email address. However, my email address also ends up in the 'from' column.The 'reply-from' address is nowhere to be found;so I don't have any address with which I can send my reply, as both of them have just my email address. What am I doing wrong here? Is there some set-up in my TOOLOPTIONS set-up incorrectly? The set-up in OPTIONS is pretty difficult to understand and it doesn't offer any 'to' or 'reply-from' choices. This is critical because I just cannot answer my emails because there is no one I can send a reply to. Please, please try to help me. If you have the answer, please email me at: [email protected] Thank you. Blessings. Shiloh

    Read the article

  • Python integer incrementing with ++

    - by Znarkus
    I've always laughed to myself when I looked back at my VB6 days, "What modern language doesn't allow incrementing with double plus signs?": number++ To my surprise I can't find anything about this in the Python docs. Must I really subject myself to number = number + 1? Doesn't people use the ++/-- notation? :-(

    Read the article

  • How to rate a connect four game situation in java

    - by MrPink
    Hey, I am trying to write a simple AI for a "Get four" game. The basic game principles are done, so I can throw in coins of different color, and they stack on each other and fill a 2D Array and so on and so forth. until now this is what the method looks like: public int insert(int x, int color) //0 = empty, 1=player1 2=player2" X is the horizontal coordinate, as the y coordinate is determined by how many stones are in the array already, I think the idea is obvious. Now the problem is I have to rate specific game situations, so find how many new pairs, triplets and possible 4 in a row I can get in a specific situation to then give each situation a specific value. With these values I can setup a "Game tree" to then decide which move would be best next (later on implementing Alpha-Beta-Pruning). My current problem is that I can't think of an efficient way to implement a rating of the current game situation in a java method. Any ideas would be greatly appreciated! greetings from Germany Mr. Pink

    Read the article

  • Adding li element only if it not already there?

    - by Legend
    I am constructing an <li> element like this: var element = $("<li></li>") .html(mHTML) .attr('id', "elemid"); I am trying to add this element to a <ul> element only if it doesn't already exist. Any ideas on how to do this? Am I supposed to use contains() to see if the ul element contain the html and then decide? For instance, <ul id="elemul"> <li id="elemli1">Element 1</li> <li id="elemli2">Element 2</li> <li id="elemli3">Element 3</li> </ul> If I try adding Element 1, it should not add it. What should I do if its a longer string (not really long but about 150 characters). Note: I cannot rely on IDs to determine the uniqueness. i.e. I might end up forming something like: <li id="elemli3">Element 1</li> Do I go about using hashmaps?

    Read the article

  • What are the books about Open-Source that everyone interested in should read?

    - by Edu Zamora
    Currently I am working and running my first Open-Source project and though I am quite happy how things are working so far, I have the feeling that a lot of things could be done better. So, what books about Open-Source would you recommend me in order to help filling this gap and making things better every day? What are the books that influenced you the most? I am especially interested in: - How to organize and run an Open-Source project - Best practices - Manage and involve users and developers - How to announce and do the releases - Legal issues

    Read the article

  • Got a question I don't understand, can anyone make sense of it?

    - by user275074
    Question on a on-line resource paper: Create javascript so that the following methods produce the output listed next it. circle = new Circle(); console.log(circle.get_area()); // 3.141592653589793 circle.set_radius(10); console.log(circle.get_area()); // 314.1592653589793 console.log(circle); // the radius of my circle is 10 and it's area is 314.1592653589793 Can anyone understand what is being asked?

    Read the article

< Previous Page | 54 55 56 57 58 59 60 61 62 63 64 65  | Next Page >