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• Java: how to initialize String[]?

  - by Heoa

  Error % javac StringTest.java StringTest.java:4: variable errorSoon might not have been initialized errorSoon[0] = "Error, why?"; Code public class StringTest { public static void main(String[] args) { String[] errorSoon; errorSoon[0] = "Error, why?"; } }

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• jQuery: Freezing/Disabling all events temporarily?

  - by Legend

  I have the following usecase: A div with some buttons When the user clicks on a button, a popup is shown and the background div is faded out to 0.5 opacity The problem is that when the popup comes in, the user is still able to click on the background buttons. At this point, I can remove the entire DIV temporarily but I don't want to do that. Is there anyway I can disable all the previously attached events and then add event handlers ONLY to the current popup? (I mean something like a close button should still work on a popup) Any suggestions?

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• C#:Saving image to folder

  - by Meko

  HI. I know this is simple question but when I use FirstPersonTestImage.Save(IIdComboBox.Text + "-" + i + ".jpg"); it works and saves file to folder where is the .exe file . But I want to save it to specific folder like /photo/IO-66/ and tryed to use String StudentPath = PhotoPath + IGroupNoComboBox.Text + "/" + IIdComboBox.Text + "/" + IIdComboBox.Text + "-" + i + ".jpg"; FirstPersonTestImage.Save(StudentPath); BUt it gives An unhandled exception of type 'System.Runtime.InteropServices.ExternalException' occurred in System.Drawing.dll How can I solve this problem? Is is about folder path ? or using "/" ? EDIT Here My code for creating and checking existing or not folder if (!System.IO.Directory.Exists(PhotoPath + "/" + IGroupNoComboBox.Text.ToString().Trim())) { Directory.CreateDirectory(PhotoPath + "/" + IGroupNoComboBox.Text.ToString().Trim()); } if (!System.IO.Directory.Exists(PhotoPath + "/" + IGroupNoComboBox.Text.ToString().Trim()+ "/" + IIdComboBox.Text.ToString().Trim() + "/")) { Directory.CreateDirectory(PhotoPath + "/" + IGroupNoComboBox.Text.ToString().Trim()+"/" + IIdComboBox.Text.ToString().Trim() + "/"); }

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• Worst aspect of Python for a newbie

  - by schickb

  I'm wondering specifically what experienced programmers thought when they started developing in Python. I'm sure the answer depends on your background, but my own personal answer is the conversion of basically anything in the language to a True/False value in boolean contexts. Resulting in "oddities" like: if x: not meaning the same thing as: if x == True: I understand why, but it bugs me, and I certainly had to think about it a bit when I first ran into it.

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• Java - Regular expression question

  - by Jacob

  I am new to regular expressions. I want to use java's replaceAll() function to replace any CSS comments in a string. Basically I want to use regex to search for anything that is surrounded by "/*" and "*/" and replace it with "".

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• Understanding Scope on Scala's For Loops (For Comprehension)

  - by T. Stone

  In Chapter 3 of Programming Scala, the author gives two examples of for loops / for comprehensions, but switches between using ()'s and {}'s. Why is this the case, as these inherently look like they're doing the same thing? Is there a reason breed <- dogBreeds is on the 2nd line in example #2? // #1 ()'s for (breed <- dogBreeds if breed.contains("Terrier"); if !breed.startsWith("Yorkshire") ) println(breed) // #2 {}'s for { breed <- dogBreeds upcasedBreed = breed.toUpperCase() } println(upcasedBreed)

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• Hash Tables - Java

  - by Antony

  Am about to do a homework, and i need to store quite a lot of information (Dictionary) in a data structure of my choice. I heard people in my classroom saying hash-tables are the way to go. How come?

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• How to print the sign + of a digit for positive numbers in Python.

  - by systempuntoout

  Is there a better way to print the + sign of a digit on positive numbers? integer1 = 10 integer2 = 5 sign = '' total = integer1-integer2 if total > 0: sign = '+' print "Total:%s%d" % (sign, total)

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• C++ - Efficient container for large amounts of searchable data?

  - by Francisco P.

  Hello, everybody! I am implementing a text-based version of Scrabble for a College project. My dictionary is quite large, weighing in at around 400.000 words (std::string). Searching for a valid word will suck, big time, in terms of efficiency if I go for a vector<string> ( O(n) ). Are there any good alternatives? Keep in mind, I'm enrolled in freshman year. Nothing TOO complex! Thanks for your time! Francisco

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• Does the OS make a significant difference for Ruby Development ?

  - by Bragaadeesh

  Hi, I have been working in Java for the past 4 years and I am currently switching over to Ruby. I am so excited about it and I feel good to finally get a hands on experience on a scripting language first time. The task assigned to me is to first pick a OS of my choice and setup a Ruby in it and study for 2 weeks. I have been developing applications in windows and Linux is not my cup of tea. Some part of me wants to try out Linux but I want to first convince myself whether OS really matters for Ruby development. If Linux does matter, which distribution can I start looking at? Please advise.

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• sending address of a variable declared on the stack?

  - by kobac

  I have a doubt concerning declaring variables, their scope, and if their address could be sent to other functions even if they are declared on the stack? class A{ AA a; void f1(){ B b; aa.f2(&b); } }; class AA{ B* mb; f2(B* b){ mb = b; //... } }; Afterwards, I use my AA::mb pointer in the code. So things I would like to know are following. When the program exits A::f1() function, b variable since declared as a local variable and placed on the stack, can't be used anymore afterwards. What happens with the validity of the AA::mb pointer? It contains the address of the local variable which could not be available anymore, so the pointer isn't valid anymore? If B class is a std::<vector>, and AA::mb is not a pointer anymore to that vector, but a vector collection itself for example. I would like to avoid copying all of it's contents in AA::f2() to a member AA::mb in line mb = b. Which solution would you recommend since I can't assign a pointer to it, because it'll be destroyed when the program exits AA::f2()

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• C++: Trouble with dependent types in templates

  - by Rosarch

  I'm having trouble with templates and dependent types: namespace Utils { void PrintLine(const string& line, int tabLevel = 0); string getTabs(int tabLevel); template<class result_t, class Predicate> set<result_t> findAll_if(typename set<result_t>::iterator begin, set<result_t>::iterator end, Predicate pred) // warning C4346 { set<result_t> result; return findAll_if_rec(begin, end, pred, result); } } namespace detail { template<class result_t, class Predicate> set<result_t> findAll_if_rec(set<result_t>::iterator begin, set<result_t>::iterator end, Predicate pred, set<result_t> result) { typename set<result_t>::iterator nextResultElem = find_if(begin, end, pred); if (nextResultElem == end) { return result; } result.add(*nextResultElem); return findAll_if_rec(++nextResultElem, end, pred, result); } } Compiler complaints, from the location noted above: warning C4346: 'std::set<result_t>::iterator' : dependent name is not a type. prefix with 'typename' to indicate a type error C2061: syntax error : identifier 'iterator' What am I doing wrong?

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• C++ STL: Trouble with string iterators

  - by Rosarch

  I'm making a simple command line Hangman game. void Hangman::printStatus() { cout << "Lives remaining: " << livesRemaining << endl; cout << getFormattedAnswer() << endl; } string Hangman::getFormattedAnswer() { return getFormattedAnswerFrom(correctAnswer.begin(), correctAnswer.end()); } string Hangman::getFormattedAnswerFrom(string::const_iterator begin, string::const_iterator end) { return begin == end? "" : displayChar(*begin) + getFormattedAnswerFrom(++begin, end); } char Hangman::displayChar(const char c) { return c; } (Eventually, I'll change this so displayChar() displays a - or a character if the user has guessed it, but for simplicity now I'm just returning everything.) When I build and run this from VS 2010, I get a popup box: Debug Assertion Failed! xstring Line: 78 Expression: string iterator not dereferenceable What am I doing wrong?

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• Type signature "Maybe a" doesn't like "Just [Event]"

  - by sisif

  I'm still learning Haskell and need help with the type inference please! Using packages SDL and Yampa I get the following type signature from FRP.Yampa.reactimate: (Bool -> IO (DTime, Maybe a)) and I want to use it for: myInput :: Bool -> IO (DTime, Maybe [SDL.Event]) myInput isBlocking = do event <- SDL.pollEvent return (1, Just [event]) ... reactimate myInit myInput myOutput mySF but it says Couldn't match expected type `()' against inferred type `[SDL.Event]' Expected type: IO (DTime, Maybe ()) Inferred type: IO (DTime, Maybe [SDL.Event]) In the second argument of `reactimate', namely `input' In the expression: reactimate initialize input output process I thought Maybe a allows me to use anything, even a SDL.Event list? Why is it expecting Maybe () when the type signature is actually Maybe a? Why does it want an empty tuple, or a function taking no arguments, or what is () supposed to be?

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• Java: ListA.addAll(ListB) fires NullPointerException?

  - by HH

  The err part is Capitalized in the code, it also comes in foreaching. Because of the abstract list, it cannot be initialized, declaration is in a static field. The lists have the same type. import java.util.*; public class Test { public static final List<String> highPrio = Arrays.asList("*","/"); public static List<String> ops; public static void main(String[] args) { //ERROR HERE, why do it throw nullPointer? ops.addAll(highPrio); for(String s : ops) { System.out.println(s); } } }

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• C++ - How to efficiently find out if any string in a vector can be assembled from a set of letters

  - by Francisco P.

  Hello, everyone! I am implementing a text-based version of Scrabble for a college project. I have a vector containing around 400K strings (my dictionary), and, at some point in every turn, I'm going to have to check if there's still a word in the dictionary which can be formed with the pieces in the player's hand. I'm checking if the player has any move left... If not, it's game over for the player in question... My only solution to this is iterating through the string, one by one, and using a sub-routine I have to check if the string in question can be formed from the player's pieces. I'll implement a quickfail checking if the user has any vowels, but it'll still be woefully inefficient. Any suggestions? Thanks for your time!

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• Importing data from a text file using python

  - by Will

  I have a text file containing data in rows and columns (~17000 rows in total). Each column is a uniform number of characters long, with the 'unused' characters filled in by spaces. For example, the first column is 11 characters long, but the last four characters in that column are always spaces (so that it appears to be a nice column when viewed with a text editor). Sometimes it's more than four if the entry is less than 7 characters. The columns are not otherwise separated by commas, tabs, or spaces. They are also not all the same number of characters (the first two are 11, the next two are 8 and the last one is 5 - but again, some are spaces). What I want to do is import the entires (which are numbers) in the last two columns if the second column contains the string 'OW' somewhere in it. Any help would be greatly appreciated.

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• PHP Session Array Value keeps showing as "Array"

  - by Nerathas

  Hello, When sending data from a form to a second page, the value of the session is always with the name "Array" insteed of the expected number. The data should get displayed in a table, but insteed of example 1, 2, 3 , 4 i get : Array, Array, Array. (A 2-Dimensional Table is used) Is the following code below a proper way to "call" upon the stored values on the 2nd page from the array ? $test1 = $_SESSION["table"][0]; $test2 = $_SESSION["table"][1]; $test3 = $_SESSION["table"][2]; $test4 = $_SESSION["table"][3]; $test5 = $_SESSION["table"][4]; What exactly is this, and how can i fix this? Is it some sort of override that needs to happen? Best Regards.

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• C++ Inheritance and Constructors

  - by DizzyDoo

  Hello, trying to work out how to use constructors with an inherited class. I know this is very much wrong, I've been writing C++ for about three days now, but here's my code anyway: clientData.h, two classes, ClientData extends Entity : #pragma once class Entity { public: int x, y, width, height, leftX, rightX, topY, bottomY; Entity(int x, int y, int width, int height); ~Entity(); }; class ClientData : public Entity { public: ClientData(); ~ClientData(); }; and clientData.cpp, which contains the functions: #include <iostream> #include "clientData.h" using namespace std; Entity::Entity(int x, int y, int width, int height) { this->x = x; this->y = y; this->width = width; this->height = height; this->leftX = x - (width/2); this->rightX = x + (width/2); this->topY = y - (height/2); this-bottomY = y + (height/2); } Entity::~Entity() { cout << "Destructing.\n"; } ClientData::ClientData() { cout << "Client constructed."; } ClientData::~ClientData() { cout << "Destructing.\n"; } and finally, I'm creating a new ClientData with: ClientData * Data = new ClientData(32,32,32,16); Now, I'm not surprised my compiler shouts errors at me, so how do I pass the arguments to the right classes? The first error (from MVC2008) is error C2661: 'ClientData::ClientData' : no overloaded function takes 4 arguments and the second, which pops up whatever changes I seem to make is error C2512: 'Entity' : no appropriate default constructor available Thanks.

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• I need help to automate my concatenate to change daily without having to manually input the new data

  - by Harold Nottingham

  Hi there I use concatenate to pull data together from different cells in my spreadsheet. Since my data changes daily, I want the formula to also change daily without having to manually input the new cell in the concatenate formula. I am looking for a way to do this but not sure how. Can anyone out there help me out please!? I appreciate the assistance in advance!

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• .htaccess: RewriteCond syntax?

  - by Rosarch

  I'm using Drupal 6. Typically, when the user requests a URL for which Drupal has no response, it uses index.php as the error document. However, I'd like to suspend this behavior for a specific URL. How can I do this? RewriteCond %{REQUEST_FILENAME} !=fail RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteCond %{REQUEST_URI} !=/favicon.ico RewriteRule ^(.*)$ index.php?q=$1 [L,QSA] Where "fail" is the path I want to block. So www.example.com/fail should result in a 404. Incidentally, what does [L, QSA] do? I've looked at documentation without luck.

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• Ruby getting the diagonal elements in a 2d Array

  - by Calm Storm

  Hi, I was trying some problems with my 2D ruby array and my LOC reduces a lot when I do array slicing. So for example, require "test/unit" class LibraryTest < Test::Unit::TestCase def test_box array = [[1,2,3,4],[3,4,5,6], [5,6,7,8], [2,3,4,5]] puts array[1][2..3] # 5, 6 puts array[1..2][1] # 5, 6, 7, 8 end end I want to know if there is a way to get a diagonal slice? Lets say I want to start at [0,0] and want a diagonal slice of 3. Then I would get elements from [0,0], [1,1], [2,2] and I will get an array like [1,4,7] for example above. Is there any magic one-liner ruby code that can achieve this? 3.times do {some magic stuff?}

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• C++: Question about freeing memory

  - by Martijn Courteaux

  On Learn C++, they wrote this to free memory: int *pnValue = new int; // dynamically allocate an integer *pnValue = 7; // assign 7 to this integer delete pnValue; pnValue = 0; My question is: "Is the last statement needed to free the memory correctly, completly?" I thought that the pointer *pnValue was still on the stack and new doesn't make any sense to the pointer. And if it is on the stack it will be cleaned up when the application leaves the scope (where the pointer is declared in), isn't it?

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• Binding a collection to Listbox

  - by Blub

  Hi, I basically started today with WPF, and I'm astounded by how difficult it is to do binding. I have an array of Textboxes, in an ObservableCollection, and just want to bind that in my Listbox, so that they arrange themselves vertically. I have fiddled around with this for 3 already, can you help? I'm working in a Wpf "UserControl", not a window as so many tutorials seem to rely on.

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• Python to extract data from a file

  - by user297003

  Hi, I am new to python. I am trying to extract the text between that has specific text file: ---- data1 data1 data1 extractme ---- data2 data2 data2 ---- data3 data3 extractme ---- and then dump it to text file so that ---- data1 data1 data1 extractme --- data3 data3 extractme --- Thanks for the help.

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