Search Results

Search found 7494 results on 300 pages for 'unused variables'.

Page 212/300 | < Previous Page | 208 209 210 211 212 213 214 215 216 217 218 219  | Next Page >

• Is it ok to store large objects (java component for example) in an Application variable?

  - by DustMason

  I am developing an app right now which creates and stores a connection to a local XMPP server in the Application scope. The connection methods are stored in a cfc that makes sure the Application.XMPPConnection is connected and authorized each time it is used, and makes use of the connection to send live events to users. As far as I can tell, this is working fine. BUT it hasn't been tested under any kind of stress. My question is: Will this set up cause problems later on? I only ask because I can't find evidence of other people using Application variables in this way. If I weren't using railo I would be using CF's event gateway instead to accomplish the same task.

  Read the article

• "Single NSMutableArray" vs. "Multiple C-arrays" --Which is more Efficient/Practical?

  - by RexOnRoids

  Situation: I have a DAY structure. The DAY structure has three variables or attributes: a Date (NSString*), a Temperature (float), and a Rainfall (float). Problem: I will be iterating through an array of about 5000 DAY structures and graphing a portion of these onto the screen using OpenGL. Question: As far as drawing performance, which is better? I could simply create an NSMutableArray of DAY structures (NSObjects) and iterate on the array on each draw call -- which I think would be hard on the CPU. Or, I could instead manually manage three different C-Arrays -- One for the Date String (2-Dimensional), One for the temperature (1-Dimensional) and One for the Rainfall (1-Dimensional). I could keep track of the current Day by referencing the current index of the iterated C-Arrays.

  Read the article

• Zend Server CE Apache mod_rewrite REQUEST_FILENAME SCRIPT_FILENAME Problem

  - by liumiuyong

  Hi,there! I use this .htaccess file in a project: RewriteCond %{SCRIPT_FILENAME} !-f RewriteCond %{SCRIPT_FILENAME} !-d RewriteRule ^(.*)$ index.php/$1 [L] It works well in Apache 2.2 Recently I started to use Zend Server CE , the ReWrite Rule didn't work ! And this works: RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ index.php/$1 [L] This is what Apache's document say: The variables SCRIPT_FILENAME and REQUEST_FILENAME contain the same value - the value of the filename field of the internal request_rec structure of the Apache server. The first name is the commonly known CGI variable name while the second is the appropriate counterpart of REQUEST_URI (which contains the value of the uri field of request_rec). Anyone can figure out why? Appreciate!

  Read the article

• Refactoring PL/SQL triggers - extract procedures

  - by Juraj

  Hello, we have application where database contains large parts of business logic in triggers, with a update subsequently firing triggers on several other tables. I want to refactor the mess and wanted to start by extracting procedures from triggers, but can't find any reliable tool to do this. Using "Extract procedure" in both SQL Developer and Toad failed to properly handle :new and :old trigger variables. If you had similar problem with triggers, did you find a way around it? EDIT: Ideally, only columns that are referenced by extracted code would be sent as in/out parameters, like: Example of original code to be extracted from trigger: ..... if :new.col1 = some_var then :new.col1 := :old.col1 end if ..... would become : procedure proc(in old_col1 varchar2, in out new_col1 varchar2, some_var varchar2) is begin if new_col1 = some_var then new_col1 := old_col1 end if; end; ...... proc(:old.col1,:new.col1, some_var);

  Read the article

• Why is volatile not considered useful in multithreaded C or C++ programming?

  - by Michael E

  As demonstrated in this answer I recently posted, I seem to be confused about the utility (or lack thereof) of volatile in multi-threaded programming contexts. My understanding is this: any time a variable may be changed outside the flow of control of a piece of code accessing it, that variable should be declared to be volatile. Signal handlers, I/O registers, and variables modified by another thread all constitute such situations. So, if you have a global int foo, and foo is read by one thread and set atomically by another thread (probably using an appropriate machine instruction), the reading thread sees this situation in the same way it sees a variable tweaked by a signal handler or modified by an external hardware condition and thus foo should be declared volatile (or, for multithreaded situations, accessed with memory-fenced load, which is probably a better a solution). How and where am I wrong?

  Read the article

• Why in Objective-C, we use self = [super init] instead of just [super init]?

  - by ????

  In a book, I saw that if a subclass is overriding a superclass's method, we may have self = [super init]; First, is this supposed to be done in the subclass's init method? Second, I wonder why the call is not just [super init]; ? I mean, at the time of calling init, the memory is allocated by alloc already (I think by [Foobar alloc] where Foobar is the subclass's name. So can't we just call [super init] to initialize the member variables? Why do we have to get the return value of init and assign to self? I mean, before calling [super init], self should be pointing to a valid memory allocation chuck... so why assigning something to self again? (if assigning, won't [super init] just return self's existing value?)

  Read the article

• How to tell a UITableView to preload all Rows?

  - by Infinite

  Is there a way to tell a UITableView to preload all rows? The tableView is supposed to show several comments (up to 80 comments). So my CommentCell uses a Setter to adapt the cell to a specific comment. -(void)setComment:(Comment *)newComment { if (newComment != comment) { [comment release]; comment = [newComment retain]; /* * set the cells view variables here */ } } This specific setter takes quite a bunch of processing resources and scrolling gets kinda laggy. I am using a comment-specific reuseIdentifier instead of a static cellIdentifier when calling dequeueReusableCellWithIdentifier: in order to assure, that "newComment" equals the old "comment". And in fact this does work great when scrolling over cells which have already been loaded. But when scrolling through the comments for the first time, it still lags like hell. Which leads me to my question: Is there a way to tell the tableview to preload all cells? (which I doubt) or Do I have to implement my own cache instead of relying on "dequeueReusableCellWithIdentifier:"?

  Read the article

• Insert problem using ADO with classic ASP

  - by Kemal Akcali

  ' Setting variables Dim con, sql_insert, data_source data_source = "project_db" sql_insert = "insert into cart ( UserID,Count,ProductName,ProductDescription,ProductPrice) values ('"&user_id&"','"&count&"','"&product_name&"','"&product_description&"','"&product_price&"')" ' Creating the Connection Object and opening the database Set con = Server.CreateObject("ADODB.Connection") con.Open data_source ' Executing the sql insertion code con.Execute sql_insert ' Done. Now Close the connection con.Close Set con = Nothing AS you can see , it is a simple code . and it worked in my local host for 5 or 6 times. but now it didn't work. What's the problem ? I think , it's about my database or memory. i setup 2 different iis in 2 different computer and they behave same... please help.. Thanks

  Read the article

• Unique constraint on more than 10 columns

  - by tk

  I have a time-series simulation model which has more than 10 input variables. The number of distinct simulation instances would be more than 1 million, and each simulation instance generates a few output rows every day. To save the simulation result in a relational database, i designed tables like this. Table SimulationModel { simul_id : integer (primary key), input0 : string or numeric, input1 : string or numeric, ...} Table SimulationOutput { dt : DateTime (primary key), simul_id : integer (primary key), output0 : numeric, ...} My question is, is it fine to put an unique constraint on all of the input columns of SimulationModel table? If it is not a good idea, then what kind of other options do i have to make sure each model is unique?

  Read the article

• Inheritance - initialization problem

  - by dumbquestion

  I have a c++ class derived from a base class in a framework. The derived class doesn't have any data members because I need it to be freely convertible into a base class and back - the framework is responsible for loading and saving the objects and I can't change it. My derived class just has functions for accessing the data. But there are a couple of places where I need to store some temporary local variables to speed up access to data in the base class. mydata* MyClass::getData() { if ( !m_mydata ) { // set to NULL in the constructor m_mydata = some_long_and complex_operation_to_get_the_data_in_the_base() } return m_mydata; } The problem is if I just access the object by casting the base class pointer returned from the framework to MyClass* the ctor for MyClass is never called and m_mydata is junk. Is there a way of only initializing the m_mydata pointer once?

  Read the article

• Is it inefficient to access a python class member container in a loop statement?

  - by Dave

  Hi there. I'm trying to adopt some best practices to keep my python code efficient. I've heard that accessing a member variable inside of a loop can incur a dictionary lookup for every iteration of the loop, so I cache these in local variables to use inside the loop. My question is about the loop statement itself... if I have the following class: class A(object): def init(self) self.myList = [ 'a','b','c', 'd', 'e' ] Does the following code in a member function incur one, or one-per-loop-iteration (5) dictionary lookups? for letter in self.myList: print letter IE, should I adopt the following pattern, if I am concerned about efficiency... localList = self.myList for letter in localList: print letter or is that actually LESS efficient due to the local variable assign? Note, I am aware that early optimization is a dangerous pitfall if I'm concerned about the overall efficiency of code development. Here I am specifically asking about the efficiency of the code, not the coding. Thanks in advance! D

  Read the article

• Phase REST XML into variable

  - by 001

  I want to get a response from the REST XML web service, and phase it into variables so I can use them in my program. 1) How come this code does not work? I get an empty string... // Get response string ws_response=""; using (HttpWebResponse response = request.GetResponse() as HttpWebResponse) { // Get the response stream StreamReader reader = new StreamReader(response.GetResponseStream()); // web service response string ws_response = reader.ReadToEnd; // <---???? I get an empty string // do phasing here (ie XML element into variable) etc.. // }

  Read the article

• Sorting a value pair in Javascript

  - by Bradley M. Davis

  I must be missing the proper term or else I'm sure I could find the answer by searching... in any case, here's what I want to do. Through javascript, I get four variables (A, B, C, and D) that I would like to sort, and still keep track of the variable name (since it's encoded with meaning information). Sample Data: A = 2; B = 1; C = 4; D = 3; What I need to do now is sort them in value order (4,3,2,1) such that I can actually know the variable name ordering (C,D,A,B).

  Read the article

• Retrieve a static variable using its name dynamically using reflection

  - by user2538438

  How to retrieve a static variable using its name dynamically using Java reflection? If I have class containing some variables: public class myClass { string [][] cfg1= {{"01"},{"02"},{"81"},{"82"}}; string [][]cfg2= {{"c01"},{"c02"},{"c81"},{"c82"}}; string [][] cfg3= {{"d01"},{"d02"},{"d81"}{"d82"}}; int cfg11 = 5; int cfg22 = 10; int cfg33 = 15; } And in another class I want variable name is input from user: class test { Scanner in = new Scanner(System.in); String userInput = in.nextLine(); // get variable from class myClass that has the same name as userInput System.out.println("variable name " + // correct variable from class) } Using reflection. Any help please?

  Read the article

• Nested loop with dependent bounds trip count

  - by aaa

  hello. just out of curiosity I tried to do the following, which turned out to be not so obvious to me; Suppose I have nested loops with runtime bounds, for example: t = 0 // trip count for l in 0:N for k in 0:N for j in max(l,k):N for i in k:j+1 t += 1 t is loop trip count is there a general algorithm/way (better than N^4 obviously) to calculate loop trip count? I am working on the assumption that the iteration bounds depend only on constant or previous loop variables.

  Read the article

• I don't get this C/C++ Joke

  - by Buttercup

  After reading this article on thedailywtf.com, I'm not sure that I really got the joke. It says there that some guy changed the code from int function() { int x; char data_string[15]; ... x = 2; strcpy(data_string,"data data data"); ... } to int function() { int x = 2; char data_string[15] = "data data data"; ... } everywhere in the code and that for some reason did inflate the size of the executable from 1 to 2 CDs (or maybe it didn't do that?). Obviously I'm not familiar enough with C/C++ to get this joke, but what seems strangest is that the 2nd code listing seems "cleaner"—at least from what I've been told in school (that is that initializing variables is a good thing, not a bad one).

  Read the article

• Keeping Computer Science Writing Accessible and Eloquent

  - by Federer

  This question is particularly aimed at descriptions and explanations of what is happening in a computer program, as well as any general advice or approaches for undertaking technical reports in Computer Science at both undergraduate and graduate levels. You see, I am having particular difficulty in the best way to explain what is happening. As in, given any given program from a multi-agent system to a standard webservice, the best and most eloquent way to say exactly what is going on, the logic behind it and it's respective justifications. Should I avoid saying class names? Avoid specifying methods? Keep referring to class variables and any particular references? I'm banging my head against the wall at trying to keep a solid technical foundation and making it accessible to people of all backgrounds. Apologies for the rather vague question. Cheers.

  Read the article

• how does "recent history" work on sites for php? (PHP)

  - by ggfan

  I'm not sure if there is an explanation on SO for beginners, but if so, could you provide the links. I am interested in creating a "recent viewed" function that shows what links they clicked on before. I'm not sure if this is the 'correct' way to do it, but this is what I have so far... user clicks on a link(say ad.php?posting_id=12). if the user doesn't click on the link, no cookie or session is stored for the link if the user clicks on the link, it sets a cookie for $_cookie['ad.php?posting_id=22'] Each time the user clicks, more cookies are set In the recent viewed function, it gets all the $_cookie variables and displays them. if the user wants to clear the history, just destroy all the cookies I'm not sure if this is the way to do it, but is the viable? If not, what are the steps to create a "recent viewed" function

  Read the article

• Factory vs instance constructors

  - by Neil N

  I can't think of any reasons why one is better than the other. Compare these two implementations: public class MyClass { public myClass(string fileName) { // some code... } } as opposed to: public class MyClass { private myClass(){} public static Create(string fileName) { // some code... } } There are some places in the .Net framework that use the static method to create instances. At first I was thinking, it registers it's instances to keep track of them, but regular constructors could do the same thing through the use of private static variables. What is the reasoning behind this style?

  Read the article

• Unable to access static var from Document Class in AS3

  - by omidomid

  I have a Document class called "CityModule", and an asset with class "City". Below is the coe for each. For some reason, I am unable to access the static variables of the City class from CityModule: CityModule.as: package { public class CityModule extends MovieClip { public function CityModule() { var buildings:Array = City.getBuildings(); } } } } City.as: package { import flash.display.MovieClip; public class City extends MovieClip { private static var _buildings:Array = [ {className:'City.Generic1', type:'generic'}, {className:'City.Generic2', type:'generic'}, {className:'City.Generic3', type:'generic'} ]; public function City(){ //empty } public static function getBuildings():Array{ return _buildings; } } } Doing this gives me a "Call to a possibly undefined method getBuildings" error. If I instantiate an instance of City, I can see any public/ getters/ setters perfectly fine. But static isn't working...

  Read the article

• How much memory is reserved when i declare a string?

  - by Bhagya

  What exactly happens, in terms of memory, when i declare something like: char arr[4]; How many bytes are reserved for arr? How is null string accommodated when I 'strcpy' a string of length 4 in arr? I was writing a socket program, and when I tried to suffix NULL at arr[4] (i.e. the 5th memory location), I ended up replacing the values of some other variables of the program (overflow) and got into a big time mess. Any descriptions of how compilers (gcc is what I used) manage memory?

  Read the article

• Do I need to install Glassfish?

  - by Ayusman

  Hi, I am new to glassfish server. i have a question on glassfish usage: can I just use glassfish like a tomcat server without needing an installation? where in, I just take a folder containing glassfish folders, jars etc... dump it in a folder location setup a few environment variables and it runs.. just like tomcat? is it possible with glassfish? also does glassfish installation does any other background things like creating registry entries etc other than creating the glassfish folder structure? TIA Ayusman

  Read the article

• How to pass a value between Silverlight pages for WP7?

  - by Sebastian Gray

  I've got a MainPage.xaml page a Detail.xaml page. I've passed variables to the Detail.xaml from MainPage.xaml by using a static variable and referencing it in Detail.xaml (the detail page is acting like a dialog). However once I've updated the content of another object, I want to call a method in MainPage.xaml to refresh the content of that page using the updated object from the Detail.xaml page. I assume I am not using the correct paradigm for this and should probably be using MVVM or something but I'm not familiar with the implementation and was hoping there was a simple way to do this?

  Read the article

• Manage bad_alloc exception in C++ construtor

  - by Jimmy zhang

  I have Java experience and recently am doing some C++ coding. My question is that if I have class A, in which I have to instantiate class B and class C as two of the member variables of A. If in the constructor of A, should I assume that allocations of class B and C never fail, and handle the bad allocation exception in the destructor of A? If I don't make that assumption, meaning that I add some try catch block to catch bad_alloc of class B and class C, then if the allocation exception occurs, should I do clean up in the constructor of A? What are the recommended practices? If "new" generates a bad allocation, what value does the pointer carry?

  Read the article

• Should I always release self for failed init methods?

  - by leo

  Should I always release self when there is a failure inside init, or should I only do so if I have initialized instance variables first? To put it another way, is this pattern valid? Is there a time when I shouldn't release self inside an init method, or should I assume that if the control flow enters init, self has at least a retain count of 1? - (id)init { if ((self = [super init]) == nil) { [self release]; return nil; } //do some init stuff if (somethingFailed) { [self release]; return nil; } return self; }

  Read the article

< Previous Page | 208 209 210 211 212 213 214 215 216 217 218 219  | Next Page >