Search Results

Search found 16643 results on 666 pages for 'stackoverflow answer'.

Page 447/666 | < Previous Page | 443 444 445 446 447 448 449 450 451 452 453 454  | Next Page >

• Reusing of a PreparedStatement between methods?

  - by MRalwasser

  We all know that we should rather reuse a JDBC PreparedStatement than creating a new instance within a loop. But how to deal with PreparedStatement reuse between different method invocations? Does the reuse-"rule" still count? Should I really consider using a field for the PreparedStatement or should I close and re-create the prepared statement in every invocation? (Of course an instance of such a class would be bound to a Connection which might be a disadvantage) I am aware that the ideal answer might be "it depends". But I am looking for a best practice for less experienced developers that they will do the right choice in most of the cases.

  Read the article

• Which libraries use the "We Know Where You Live" optimization for std::make_shared?

  - by KnowItAllWannabe

  Over two years ago, Stephan T. Lavavej described a space-saving optimization he implemented in Microsoft's implementation of std::make_shared, and I know from speaking with him that Microsoft has nothing against other library implementations adopting this optimization. If you know for sure whether other libraries (e.g., for Gnu C++, Clang, Intel C++, plus Boost (for boost::make_shared)) have adopted this implementation, please contribute an answer. I don't have ready access to that many make_shared implementations, nor am I wild about digging into the bowels of the ones I have to see if they've implemented the WKWYL optimization, but I'm hoping that SO readers know the answers for some libraries off-hand. I know from looking at the code that as of Boost 1.52, the WKWYL optimization had not been implemented, but Boost is now up to version 1.55. Note that this optimization is different from std::make_shared's ability to avoid a dedicated heap allocation for the reference count used by std::shared_ptr. For a discussion of the difference between WKWYL and that optimication, consult this question.

  Read the article

• Why exactly is calling the destructor for the second time undefined behavior in C++?

  - by sharptooth

  As mentioned in this answer simply calling the destructor for the second time is already undefined behavior 12.4/14(3.8). For example: class Class { public: ~Class() {} }; // somewhere in code: { Class* object = new Class(); object->~Class(); delete object; // UB because at this point the destructor call is attempted again } In this example the class is designed in such a way that the destructor could be called multiple times - no things like double-deletion can happen. The memory is still allocated at the point where delete is called - the first destructor call doesn't call the ::operator delete() to release memory. For example, in Visual C++ 9 the above code looks working. Even C++ definition of UB doesn't directly prohibit things qualified as UB from working. So for the code above to break some implementation and/or platform specifics are required. Why exactly would the above code break and under what conditions?

  Read the article

• Looping differences in Ruby using Range vs. Times

  - by jbjuly

  I'm trying to solve a Project Euler problem using Ruby, I used 4 different looping methods, the for-loop, times, range and upto method, however the for-loop and times method only produces the expected answer, while the range and upto method does not. I'm assuming that they are somewhat the same, but I found out it's not. Can someone please explain the differences between these methods? Here's the looping structure I used # for-loop method for n in 0..1 puts n end 0 1 => 0..1 # times method 2.times do |n| puts n end 0 1 => 2 # range method (0..1).each do |n| puts n end 0 1 => 0..1 # upto method 0.upto(1) do |n| puts n end 0 1 => 0

  Read the article

• JSF (and friends) tags vs. traditional html tags

  - by H3wh0s33ks

  So this question came up today and I didn't have a specific or scientific answer. What are the costs associated with using jsf (or tomahawk, faclets, etc., etc.) tags in place of traditional html tags. My gut reaction is that you should use jsf tags in situations where you need the additional functionality they provide, and use traditional tags when you don't. Also I feel like jsf tags would require more resources (since the server has to take them and rerender them as html anyways) than html. Does anybody know what the cost actually is (as far as time and memory)? Also useful information is what is the convention that is in use, pure jsf or a mixture of the two?

  Read the article

• Can I do everything in C that C++ and C# and Java can do?

  - by Sahat

  Is it possible to write in C programming language everything that you could write in other languages such as Java, C# or C++. If that's the case why don't schools these days teach C instead of Java? Ok the main reason why I am asking is because I don't want to tie down to a single programming language and platform (.NET and C# or Obj-C and Cocoa). Perhaps I am confusing a programming language with a framework? If anyone could clarify all this for me, I'd certainly vote for your answer.

  Read the article

• where is "create instance" menu in visual studio 2010?

  - by austin powers

  Hi, in visual studio 2008 there is a sub-menu called "create instance" which is resides in class designer. Today I've opened VS.net 2010 and then opened class designer and create my class over there and when I wanted to test my class with the help of "create instance" option there was no such option available in vs.net 2010. and I've googled about it a little bit but no answer at all so I decided to mention about it here. where can I find this menu in vs.net 2010? regards.

  Read the article

• sloving Algorithm notation

  - by neednewname

  Use big-O notation to classify the traditional grade school algorithms for addition and multiplication. That is, if asked to add two numbers each having N digits, how many individual additions must be performed? If asked to multiply two N-digit numbers, how many individual multiplications are required Suppose f is a function that returns the result of reversing the string of symbols given as its input, and g is a function that returns the concatenation of the two strings given as its input. If x is the string hrwa, what is returned by g(f(x),x)? Explain your answer - don't just provide the result!

  Read the article

• Write the longest possible loop.

  - by Abhay

  Hello Group, Recently I was asked this question in a technical discussion. What is the longest possible loop that can be written in a programming language? This loop has to be as long as possible and yet not an infinite loop and should not end-up crashing the program (Recursion etc...) I honestly did not know how to attack this problem, so I asked him if is it practically possible. He said using some computer science concepts, you can arrive at a hypothetical number which may not be practical but nevertheless it will still not be infinite. Anyone here; knows how to analyse / attack this problem. P.S. Choosing some highest limit for a type that can store the highest numerical value is apparently not an answer. Thanks in advance,

  Read the article

• Trouble Getting a Locally Hosted Copy of the English Language Wiktionary to include the Translations Sections

  - by user1436026

  I used MWDumper - http://www.mediawiki.org/wiki/Mwdumper - to import the xml dump of the English Language Wiktionary (specifically the file named enwiktionary-20120930-pages-meta-current.xml,) to my local server. I have found that under the Translations section (on each page for each English word,) next to the name of each language where I should be able to see the definition in a foreign language, I instead see Template:Tø, Template:T+, or Template:T- and I am not sure why this is. As an experiment, I also used WikiTaxi - http://www.yunqa.de/delphi/doku.php/products/wikitaxi/index - with the exact same XML dump and did not have this problem when viewing under WikiTaxi.exe. I have been searching through mediawiki.org looking for the answer, but have so far not been successful. I appreciate your help

  Read the article

• Why input elements don't render the value passed in ASP.Net MVC?

  - by MediaSlayer

  This post asks this question but doesn't really give an answer, so I thought I would ask the question differently. I have a page that renders a hidden value from the model: <%=Html.Hidden("myName", model.myValue) %> Since I am passing a value in the value parameter, you would think it would output that value, but it doesn't. The code for rendering input fields has the following: string attemptedValue = (string)htmlHelper.GetModelStateValue(name, typeof(string)); tagBuilder.MergeAttribute("value", attemptedValue ?? ((useViewData) ? htmlHelper.EvalString(name) : valueParameter), isExplicitValue); Basically, if the ModelState (which contains posted values) contains a value for the "name" passed, it will use that value instead of your passed value to the helper method. In my case, I updated the model and my updated value wasn't outputted. If I pass a value to a method, I expect that value to be rendered. Am I missing something in this design or is it just wrong?

  Read the article

• How do I create a point system in a Rails/Twitter app that assigns points to users and non-authentic

  - by codyvbrown

  I'm building a question and answer application on top of twitter and I'm hitting some snags because I'm inevitably dealing with two classes of users: authenticated and non-authenticated. The site enable users to give points to other users, who may or may not be authenticated, and I want to create a site-wide point system where the application stores and displays this information on their profile. I want to save this point data to the user because that would be faster and more efficient but non-authenticated users aren't in our system, we only have the twitter handle. So instead we display the points in our system like this: @points = point.all( :select => "tag, count(*) AS count", # Return tag and count :group => 'tag', # Group by the tag :order => "2 desc", :conditions => {:twitter_handle => params[:username]}) Is there a better way to do this? Is there a better way to associate data with non-authenticated users?

  Read the article

• How does jQuery have asynchronous functions?

  - by Sam.Rueby

  I'm surprised I can't find a clear answer to this. So, in jQuery, you can do this: $(someElements).fadeOut(1000); $(someElements).remove(); Which, will start a fadeOut animation, but before it finishes executing in the 1 second duration, the elements are removed from the DOM. But how is this possible? I keep reading the JavaScript is single threaded. ( Is javascript guaranteed to be single-threaded? ) This question is not "How do I fix this?" I know I can do either: $(someElements).fadeOut(1000).promise().done(function() { $(someElements).remove();});, or even better:$(someElements).fadeOut(1000, function() { $(this).remove(); } ); What I don't understand is how JavaScript runs in a "single thread" but I'm able to use these jQuery functions that execute asynchronously and visibly see the DOM change in different places at the same time. How does it work?

  Read the article

• What lessons have you learned about using a wiki as a development tool?

  - by Vivek Kodira

  I'd asked a question a while back about ways to encourage my team to collaborate. The tool we use is a wiki. Since this is the first time we are using the wiki (formally and as a team), we are learning by committing mistakes. One of the lessons has been that a wiki isn't suitable for tracking activities. It is better to use a tool built for-the-job (will elaborate if necessary). Are there other such anti-patterns? What development tasks would you NOT recommend using a wiki for (even though it may seem suitable at first glance)? Edit: Making this a community-wiki since it is probably unlikely that there will be 'one' right answer.

  Read the article

• Toggling doesnt work inIE 7

  - by praveen

  I have two divs i need to perform toggling between two divs while doing this some of the divs in my main div are not displaying none ie7 unction initMakeAPost() { $('questionheaderid').hide(); //hiding the questions section $('MP_questionofday_txtboxid').hide();//hiding the questions answer"textbox and button" section $('recaspotheaderid').hide();//hiding the search by txtspotname and city-spots //$('footer_userpost').hide();//hiding the footer $('makeapostid').show();//show the make a post content $('btnQAPost').hide(); $('footer_userpost').hide();//Vamsi:Hiding the footer intitially $('sreetCredContainer').hide(); $('postbtnid_dead').hide(); $('askNextQuestion').hide(); //$('UploadImgContainer').show();// for upload } evn if i hide it doesnt hide in IE7

  Read the article

• javascript window.close, once again

  - by John Kjøller

  Im sorry if I havent done my research properly, - but couldnt find the answer I needed, so here goes: From my main page I open a new window using mainPlayer = window.open(); This window stays open until user clicks on a mainPlayer.close(); event. (or simply x closes the window) However, the idea is to make it possible to let the player keep playing, while browsing around the rest of the pages. But as soon as the user leaves the page that opened the mainPlayer window, the reference to the mainPlayer window seem to be lost. How do I, from the site's other pages, check if the mainPlayer window is open and close it on a click event? Thx John

  Read the article

• Implementing a live voting system

  - by Will Eddins

  I'm looking at implementing a live voting system on my website. The website provides a live stream, and I'd like to be able to prompt viewers to select an answer during a vote initiated by the caster. I can understand how to store the data in a mySQL database, and how to process the answers. However: How would I initially start the vote on the client-side and display it? Should a script be running every few seconds on the page, checking another page to see if a question is available for the user? Are there any existing examples of a real-time polling system such as what I'm looking at implementing?

  Read the article

• Google App Engine - Is os.environ reset between requests?

  - by Ian Charnas

  Hello I can't think of a way to test this and was hoping someone here knew the answer... I'm storing some request-specific data in os.environ, and was wondering if that data was going to leak to other requests. Does anyone know? Yes I realize that it's normal to use request.environ for this, and usually I do, but I want to store the currently authorized user ID (I'm using custom auth, not GAE auth) inside os.environ so that the models know the currently logged in user (remember, they don't have access to request.environ) without me having to pass the request object to just about every single model method. any help would be greatly appreciated Ian

  Read the article

• interview questions for a test lead

  - by PJ

  Maybe this question has been asked although I didn't find the answer. I am going to attend an interview for a test lead. can you tell me the pattern of questions I will have to face other than the normal question that I was facing previously like What is Software testing? What is Bug life cycle? or Grilling me on my project experience. Also I wnat to know when they are going to hire me for a test lead what would they want to see as an extra add ons?

  Read the article

• An exception to the "only one implementation" rule ?

  - by ereOn

  While I was reading the accepted answer of this question, I had the following question: Typically, methods are defined in header files (.hpp or whatever), and implementation in source files (.cpp or whatever). One of the main reasons it is bad practice to ever include a "source file" (#include <source_file.cpp>) is that its methods implementation would then be duplicated, resulting in linking errors. When one writes: #ifndef BRITNEYSPEARS_HPP #define BRITNEYSPEARS_HPP class BritneySpears { public: BritneySpears() {}; // Here the constructor has implementation. }; #endif /* BRITNEYSPEARS_HPP */ He is giving the implementation of the constructor (here an "empty" implementation, but still). But why then including this header file multiple times (aka. on different source files) will not generate a "duplicate definition" error at link time ?

  Read the article

• Can NTFS-Search(An OSS project) scan any file on NTFS volume?

  - by Benjamin

  I want to apply NTFS-Search to our project. Our project have to find the files which we specified.(fast and exactly!) But I'm not sure the program(NTFS-Search) works well. What if the file specified is system file? What if the file is being opened by a process with NO_READ_SHARE_MODE? Do you think NTFS-Search can find any files? I don't know about NTFS filesystem well. So I can't find the answer myself. Is there anyone who knows that? I tried to find their email address, but I couldn't find. Thanks in advance.

  Read the article

• wxPython - wx.ChildFrame

  - by Dunwitch

  I'm sure this is simple, but I can't seem to find the answer. While using wx.MDIParentFrame, I open a new window with wx.MDIChildFrame. There is static text on the ParentFrame, and once the ChildFrame opens the text gets erased from the ParentFrame? import wx class Frame(wx.MDIParentFrame): def __init__(self): wx.MDIParentFrame.__init__(self, None, -1, "Main Window", size=(800,600), style=wx.DEFAULT_FRAME_STYLE | wx.FRAME_NO_WINDOW_MENU) menu = wx.Menu() menu.Append(100, "&New Window") menu.Append(101, "E&xit") menubar = wx.MenuBar() menubar.Append(menu, "&File") self.SetMenuBar(menubar) self.Bind(wx.EVT_MENU, self.OnNewWindow, id=100) self.Bind(wx.EVT_MENU, self.OnExit, id=101) self.Center() background_text = wx.StaticText(self, id=-1, label="This is background text", pos = (20, 250)) def OnExit(self, evt): self.Close(True) self.Destroy() def OnNewWindow(self, evt): win = wx.MDIChildFrame(self, -1, "Child Window", size = (300, 300), style=wx.DEFAULT_FRAME_STYLE ^ (wx.MAXIMIZE_BOX | wx.RESIZE_BORDER)) win.SetBackgroundColour("#BB00e0") win.Show(True) if __name__ == '__main__': app = wx.PySimpleApp() frame = Frame() frame.Show() app.MainLoop()

  Read the article

• Why does cisco IOS require domain-name to be set before SSH keys can be generated?

  - by Daniel Papasian

  Is there a technical reason why IOS requires the device's domain-name to be set (via ip domain-name) before an SSH key can be generated? Is the domain-name used in any way in the generation of the key? Is there any way to force the generation of a key before the domain name is set? UPDATE: Myself (before I posted this question) and others in your answer seem to think it may be used as either a salt or a source of entropy for the key. Wouldn't the domain-name be very predictable? This doesn't seem like a suitable source of entropy.

  Read the article

• Create instance of generic type in Java?

  - by David Citron

  Is it possible to create an instance of a generic type in Java? I'm thinking based on what I've seen that the answer is "no" (due to type erasure), but I'd be interested if anyone can see something I'm missing: class SomeContainer<E> { E createContents() { return what??? } } EDIT: It turns out that Super Type Tokens could be used to resolve my issue, but it requires a lot of reflection-based code, as some of the answers below have indicated. I'll leave this open for a little while to see if anyone comes up with anything dramatically different than Ian Robertson's Artima Article.

  Read the article

• jQuery $.post & $.append & IE6

  - by Jim

  I'm having a weird problem with jQuery and IE6. Script works on IE7+ and with all other browsers I have tried it. I can't post the full script, but what it does is this: $.post("file.php",{'foo':'bar'},function(data){ $('#target').append(data) }) When I run the code in IE6, #target just shows ? and a white char with a hole in the middle. I have no idea what this second char is. My initial thought was that this was some sort of content-type problem because the file.php just echoes answer without any header information. I added Content-type: text/html with header() but didn't help. Any suggestions?

  Read the article

< Previous Page | 443 444 445 446 447 448 449 450 451 452 453 454  | Next Page >