Search Results

Search found 8019 results on 321 pages for 'while loop'.

Page 274/321 | < Previous Page | 270 271 272 273 274 275 276 277 278 279 280 281  | Next Page >

  • how to make this in python

    - by user2980882
    The number reduction game Rules of the game: ? The first player to write a 0 wins. ? To start the game, Player 1 picks any whole number greater than 1, say 18. ? The players take turns reducing the number by either: o Subtracting 1 from the number his/her opponent just wrote, OR o Halving the number his/her opponent just wrote, rounding down if necessary. Write a Python program that lets two players play the number reduction game. Your program should: 1. Ask Player 1 to enter the starting number. 2. Use a while-loop to allow the players to take turns reducing the number until someone wins. 3. Each time a player enters a positive number (not 0), inform the other player what his/her choices are and ask him/her to enter the next number. 4. Declare the winner when someone enters 0. Example session: Player 1, enter a number greater than 1: 16 Player 2, your choices are 15 or 8: 15 Player 1, your choices are 14 or 7: 7 Player 2, your choices are 6 or 3:3 Player 1, your choices are 2 or 1:2 Player 2, your choices are 1 or 1:1 Player 1, your choices are 0 or 0:0 Player 1 wins

    Read the article

  • php weird bug where an array is not an array !

    - by iko
    I've been going mad trying to figure out why an array would not be an array in php. For a reason I can't understand I have a bug in a smarty class. The code is this : $compiled_tags = array(); for ($i = 0, $for_max = count($template_tags); $i < $for_max; $i++) { $this->_current_line_no += substr_count($text_blocks[$i], "\n"); // I tried array push instead to see // bug is here array_push($compiled_tags,$this->_compile_tag($template_tags[$i])); //$compiled_tags[] = $this->_compile_tag($template_tags[$i]); $this->_current_line_no += substr_count($template_tags[$i], "\n"); } the error message is Warning: array_push() expects parameter 1 to be array, integer given in .... OR before with [] Warning: Cannot use a scalar value as an array in .... I trying a var_debug on $compiled_tags and as soon I enter the for loop is not an array anymore but an integer. I tried renaming the variable, but same problem. I'm sure is something simple that I missed but I can't figure it out. Any help is (as always) welcomed !

    Read the article

  • How to iteratively generate k elements subsets from a set of size n in java?

    - by Bea Metitiri
    Hi, I'm working on a puzzle that involves analyzing all size k subsets and figuring out which one is optimal. I wrote a solution that works when the number of subsets is small, but it runs out of memory for larger problems. Now I'm trying to translate an iterative function written in python to java so that I can analyze each subset as it's created and get only the value that represents how optimized it is and not the entire set so that I won't run out of memory. Here is what I have so far and it doesn't seem to finish even for very small problems: public static LinkedList<LinkedList<Integer>> getSets(int k, LinkedList<Integer> set) { int N = set.size(); int maxsets = nCr(N, k); LinkedList<LinkedList<Integer>> toRet = new LinkedList<LinkedList<Integer>>(); int remains, thresh; LinkedList<Integer> newset; for (int i=0; i<maxsets; i++) { remains = k; newset = new LinkedList<Integer>(); for (int val=1; val<=N; val++) { if (remains==0) break; thresh = nCr(N-val, remains-1); if (i < thresh) { newset.add(set.get(val-1)); remains --; } else { i -= thresh; } } toRet.add(newset); } return toRet; } Can anybody help me debug this function or suggest another algorithm for iteratively generating size k subsets? EDIT: I finally got this function working, I had to create a new variable that was the same as i to do the i and thresh comparison because python handles for loop indexes differently.

    Read the article

  • PHP : If...Else...Query

    - by Rachel
    I am executing this statement under while (($data=fgetcsv($this->fin,5000,";"))!==FALSE) Now what I want in else loop is to throw exception only for data value which did not satisfy the if condition. Right now am displaying the complete row as I am not sure how to throw exception only for data which does not satisfy the value. Code if ((strtotime($data[11]) &&strtotime($data[12])&&strtotime($data[16]))!==FALSE && ctype_digit($data[0]) && ctype_alnum($data[1]) && ctype_digit($data[2]) && ctype_alnum($data[3]) && ctype_alnum($data[4]) && ctype_alnum($data[5]) && ctype_alnum($data[6]) && ctype_alnum($data[7]) && ctype_alnum($data[8]) && $this->_is_valid($data[9]) && ctype_digit($data[10]) && ctype_digit($data[13]) && $this->_is_valid($data[14])) { //Some Logic } else { throw new Exception ("Data {$data[0], $data[1], $data[2], $data[3], $data[4], $data[5], $data[6], $data[7], $data[8], $data[9], $data[10], $data[11], $data[12], $data[13], $data[14], $data[16]} is not in valid format"); } Guidance would be highly appreciated as to how can I throw exception only for data which did not satisfy the if value.

    Read the article

  • How to delay program for a certain number of milliseconds, or until a key is pressed?

    - by Jack
    I need to delay my program's execution for a specified number of milliseconds, but also want the user to be able to escape the wait when a key is pressed. If no key is pressed the program should wait for the specified number of milliseconds. I have been using Thread.Sleep to halt the program (which in the context of my program I think is ok as the UI is set to minimise during the execution of the main method). I have thought about doing something like this: while(GetAsyncKeyState(System.Windows.Forms.Keys.Escape) == 0 || waitTime > totalWait) { Thread.Sleep(100); waitTime += 100; } As Thread.Sleep will wait until at least the time specified before waking the thread up, there will obviously be a large unwanted extra delay as it is scaled up in the while loop. Is there some sort of method that will sleep for a specified amount of time but only while a condition holds true? Or is the above example above the "correct" way to do it but to use a more accurate Sleep method? If so what method can I use? Thanks in advance for your help.

    Read the article

  • "pseudo-atomic" operations in C++

    - by dan
    So I'm aware that nothing is atomic in C++. But I'm trying to figure out if there are any "pseudo-atomic" assumptions I can make. The reason is that I want to avoid using mutexes in some simple situations where I only need very weak guarantees. 1) Suppose I have globally defined volatile bool b, which initially I set true. Then I launch a thread which executes a loop while(b) doSomething(); Meanwhile, in another thread, I execute b=true. Can I assume that the first thread will continue to execute? In other words, if b starts out as true, and the first thread checks the value of b at the same time as the second thread assigns b=true, can I assume that the first thread will read the value of b as true? Or is it possible that at some intermediate point of the assignment b=true, the value of b might be read as false? 2) Now suppose that b is initially false. Then the first thread executes bool b1=b; bool b2=b; if(b1 && !b2) bad(); while the second thread executes b=true. Can I assume that bad() never gets called? 3) What about an int or other builtin types: suppose I have volatile int i, which is initially (say) 7, and then I assign i=7. Can I assume that, at any time during this operation, from any thread, the value of i will be equal to 7? 4) I have volatile int i=7, and then I execute i++ from some thread, and all other threads only read the value of i. Can I assume that i never has any value, in any thread, except for either 7 or 8? 5) I have volatile int i, from one thread I execute i=7, and from another I execute i=8. Afterwards, is i guaranteed to be either 7 or 8 (or whatever two values I have chosen to assign)?

    Read the article

  • Binding Events rather than using onclick

    - by Abs
    Hello all, I have been told its better to bind events to elements rather than having onclicks with functions everywhere. I agree with this as it devolves more from the HTML which means cleaner and easier to debug code. But I am having trouble doing this! I loop through some data with PHP (see below) and I currently use onclick to call a function. How can I bind this onclick event to many elements using JQuery. <?php foreach($main_tags as $key=>$value){ ?> <li> <a id="<?php echo $key; ?>" href="#" onclick="tag_search('<?php echo $key; ?>'); return false;"> <?php echo $key; ?> <span class="num-active"> <?php echo $value; ?> </span> </a> </li> <?php } ?> Thanks all for any help

    Read the article

  • PHP foreach help

    - by sea_1987
    Hello I have an array that looks like this, Array ( [cfi_title] => Mr [cfi_firstname] => Firstname [cfi_surname] => Lastname [cfi_email] => [email protected] [cfi_subscribe_promotional] => [cfi_tnc] => [friendsName] => Array ( [0] => Firstname 1 [1] => Firstname 2 [2] => Firstname 3 ) [friendsEmail] => Array ( [0] => [email protected] [1] => [email protected] [2] => [email protected] ) [submit_form] => Submit ) My dilema is I need to save the values from the friendsName and friendsEmail arrays into a database, I know I can loop through them but how can I send the matching data, for example I need to save [friendsName][0] and friendsEmail][0] on the same row of database? I know I need to use a foreach but I just cannot figure out the logic.

    Read the article

  • Problem using find function in Matlab

    - by Peter Etchells
    Hi all, I have two arrays of data that I'm trying to amalgamate. One contains actual latencies from an experiment in the first column (e.g. 0.345, 0.455... never more than 3 decimal places), along with other data from that experiment. The other contains what is effectively a 'look up' list of latencies ranging from 0.001 to 0.500 in 0.001 increments, along with other pieces of data. Both data sets are X-by-Y doubles. What I'm trying to do is something like... for i = 1:length(actual_latency) row = find(predicted_data(:,1) == actual_latency(i) full_set(i,1:4) = [actual_latency(i) other_info(i) predicted_info(row,2)... predicted_info(row,3)]; end ...in order to find the relevant row in predicted_data where the look up latency corresponds to the actual latency. I then use this to created an amalgamated data set, full_set. I figured this would be really simple, but the find function keeps failing by throwing up an empty matrix when looking for an actual latency that I know is in predicted_data(:,1) (as I've double-checked during debugging). Moreover, if I replace find with a for loop to do the same job, I get a similar error. It doesn't appear to be systematic - using different participant data sets throws it up in different places. Furthermore, during debugging mode, if I use find to try and find a hard-coded value of actual_latency, it doesn't always work. Sometimes yes, sometimes no. I'm really scratching my head over this, so if anyone has any ideas about what might be going on, I'd be really grateful.

    Read the article

  • Ordering by number of rows?

    - by Rob
    Alright, so I have a table outputting data from a MySQL table in a while loop. Well one of the columns it outputs isn't stored statically in the table, instead it's the sum of how many times it appears in a different MySQL table. Sorry I'm not sure this is easy to understand. Here's my code: $query="SELECT * FROM list WHERE added='$addedby' ORDER BY time DESC"; $result=mysql_query($query); while($row=mysql_fetch_array($result, MYSQL_ASSOC)){ $loghwid = $row['hwid']; $sql="SELECT * FROM logs WHERE hwid='$loghwid' AND time < now() + interval 1 hour"; $query = mysql_query($sql) OR DIE(mysql_error()); $boots = mysql_num_rows($query); //Display the table } The above is the code displaying the table. As you can see it's grabbing data from two different MySQL tables. However I want to be able to ORDER BY $boots DESC. But as its a counting of a completely different table, I have no idea of how to go about doing that. I would appreciate any help, thank you.

    Read the article

  • Creation of model in core data on the fly

    - by user1740045
    How can we create a model in core data on the fly? I.e getting the schema of database from somewhere and then creating a Core Data Object graph? *QuesTion:* Yes thats fine, agreed with all the advantages. But, can anybody can tell practically, what is the benefit of integrating Core Data into project instead of using SQL directly. 1.No need to write SQL boiler plate code [but need to learn Core Data Model (steep curve)] 2.WE can undo and redo changes [but practically who needs it] 3.we can migrate to another schema [that can be done by SQLite as well jus need to add another field into table] 4.For say aggregation on some field in table,in Core Data we need to loop through Core Data Objects whereas in SQLite we need to first write SQLite Boiler Plate Code and then the basic aggregation SQL query,which is easy to write,only length of code will increase...But in case of Core Data (need to learn a lot). So apart from reducing the length of Code,does it actually adds value to project? or in terms of Memory Efficiency,Performance,etc.. PS: If anybody has actualy worked on Core Data(Model Creation On the Fly) , if possible share and gve pointers..thanks!

    Read the article

  • Add new element in existing object

    - by user3094292
    I am using node.js. I have to add new elements in the object before to send a response to client. user.getMatch(req.user, function(err, match){ for( k=0; k<match.length; k++){ var userId = { id : match[k].match_id }; var user = new User(userId); console.log('k: ' + k); user.getUserInfo(function(err2, info){ console.log('k here: ' + k); if(info){ match[k].foo = info[0].foo; } }); } var response = { data : match }; res.json(response); }); I want to add an element "foo" from user.getUserInfo to the object "match" that was returned by user.getMatch. And then send all the data as response to the client. But it got an error because "k" inside of user.getUserInfo is not equal to the "k" outside. I do not know why the both "k" are not equal. And how will I send a response to the client after performing the loop. Thanks for your help!

    Read the article

  • num_rows is 0 when it should be >0 for php mysqli code

    - by jpporterVA
    My num_rows is coming back as 0, and I've tried calling it several ways, but I'm stuck. Here is my code: $conn = new mysqli($dbserver, "dbuser", "dbpass", $dbname); // get the data $sql = 'SELECT AT.activityName, AT.createdOn FROM userActivity UA, users U, activityType AT WHERE U.userId = UA.userId and AT.activityType = UA.activityType and U.username = ? order by AT.createdOn'; $stmt = $conn->stmt_init(); $stmt->prepare($sql); $stmt->bind_param('s', $requestedUsername); $stmt->bind_result($activityName, $createdOn); $stmt->execute(); // display the data $numrows = $stmt->num_rows; $result=array("user activity report for: " . $requestedUsername . " with " . $numrows . " rows:"); $result[]="Created On --- Activity Name"; while ($stmt->fetch()) { $msg = " " . $createdOn . " --- " . $activityName . " "; $result[] = $msg; } $stmt->close(); There are multiple rows found, and the fetch loop process them just fine. Any suggestions on what will enable me to get the number of rows returned in the query? Suggestions are much appreciated. Thanks in advance.

    Read the article

  • Is there a faster method to match an arbitrary String to month name in Java

    - by jonc
    Hello, I want to determine if a string is the name of a month and I want to do it relatively quickly. The function that is currently stuck in my brain is something like: boolean isaMonth( String str ) { String[] months = DateFormatSymbols.getInstance().getMonths(); String[] shortMonths = DateFormatSymbols.getInstance().getShortMonths(); int i; for( i = 0; i<months.length(); ++i;) { if( months[i].equals(str) ) return true; if( shortMonths[i].equals(str ) return true; } return false; } However, I will be processing lots of text, passed one string at a time to this function, and most of the time I will be getting the worst case of going through the entire loop and returning false. I saw another question that talked about a Regex to match a month name and a year which could be adapted for this situation. Would the Regex be faster? Is there any other solution that might be faster?

    Read the article

  • C++ Template Iterator error

    - by gprime
    I am going over some code i wrote in 2006 as an undergrad. It's a simple genetic algorithm library written in C++ using templates. It use to work in 2006 when i coded it with visual studio, but now when i am trying to run it in xcode i get compile errors. This function is giving me errors: friend bool operator==(const TSPGenome<T> & t1, const TSPGenome<T> & t2) { // loop through each interator and check to see if the two genomes have the same values if(t1.genome_vec->size() != t2.genome_vec->size()) return false; else { // iterate through each vector<T>::iterator it_t1; vector<T>::iterator it_t2; it_t1 = t1.genome_vec->begin(); for(it_t2 = t2.genome_vec->begin(); it_t2 != t2.genome_vec->end(); ++it_t2, ++it_t1) { if(*it_t2 != *it_t1) return false; } } // everything seems good return true; } xcode complains about these two lines not having ; before it_t1 and it_t2. vector<T>::iterator it_t1; vector<T>::iterator it_t2; Is it because the vector type it T? I declared it in the class as follows: template <typename T> class TSPGenome : public Genome { Any help would be appreciated. Thanks!

    Read the article

  • Works for Short Input, Fails for Long Input. How to Solve?

    - by r0ach
    I've this program which finds substring in a string. It works for small inputs. But fails for long inputs. Here's the program: //Find Substring in given String #include <stdio.h> #include <string.h> main() { //Variable Initialization int i=0,j=0,k=0; char sentence[50],temp[50],search[50]; //Gets Strings printf("Enter Sentence: "); fgets(sentence,50,stdin); printf("Enter Search: "); fgets(search,50,stdin); //Actual Work Loop while(sentence[i]!='\0') { k=i;j=0; while(sentence[k]==search[j]) { temp[j]=sentence[k]; j++; k++; } if(strcmp(temp,search)==0) break; i++; } //Output Printing printf("Found string at: %d \n",k-strlen(search)); } Works for: Enter Sentence: good evening Enter Search: evening Found string at 6 Fails for: Enter Sentence: dear god please make this work Enter Search: make Found string at 25 Which is totally wrong. Can any expert find me a solution? P.S: This is kinda like reinventing the wheel since strstr() has this functionality. But I'm trying for a non-library way of doing it.

    Read the article

  • PHP Error Form - Leave Contents of Form on Redirect

    - by user1371500
    I have a simple login form in which if an error occurs such as wrong password, I need it to be able to remember the username which was entered. Would I Go about doing this PHP or Javascript as I am not allowed to use JQuery. My current PHP - (Not Including the HTML Form) <?php //MySQl Connection mysql_connect("localhost", "root", "") or die(mysql_error()); mysql_select_db("clubresults") or die(mysql_error()); //Initiates New Session - Cookie session_start(); // Start a new session // Get the data passed from the form $username = $_POST['username']; $password = md5($_POST['pass']); // Do some basic sanitizing $username = mysql_real_escape_string($username); $password = mysql_real_escape_string($password); //Performs SQL Query to retrieve Login Details from DB $sql = "select * from admin_passwords where username = '$username' and password = '$password'"; $result = mysql_query($sql) or die ( mysql_error() ); //Assigns a Variable Count to 0 $count = 0; //Exectues a loop to increment on Successful Login while ($line = mysql_fetch_assoc($result)) { $count++; } //If count is equal to 1 Redirect user to the Members Page and Set Cookie if ($count == 1) { $_SESSION['loggedIn'] = "true"; header("Location: members.php"); // This is wherever you want to redirect the user to } else { //Else Echo that login was a failure. die('Login Failed. <a href=login.php>Click Here to Try Again</a>'); } ?> Any help would be appreciated. Cheers

    Read the article

  • Dispose, when is it called?

    - by Snake
    Consider the following code: namespace DisposeTest { using System; class Program { static void Main(string[] args) { Console.WriteLine("Calling Test"); Test(); Console.WriteLine("Call to Test done"); } static void Test() { DisposeImplementation di = new DisposeImplementation(); } } internal class DisposeImplementation : IDisposable { ~DisposeImplementation() { Console.WriteLine("~ in DisposeImplementation instance called"); } public void Dispose() { Console.WriteLine("Dispose in DisposeImplementation instance called"); } } } The Dispose just never get's called, even if I put a wait loop after the Test(); invocation. So that quite sucks. I want to write a class that is straightforward and very easy to use, to make sure that every possible resource is cleaned up. I don't want to put that responsibilty to the user of my class. Possible solution: use using, or call Dispose myself(basicly the same). Can I force the user to use a using? Or can I force the dispose to be called? Calling GC.Collect(); after Test(); doesn't work either. Putting di to null doesn't invoke Dispose either. The Deconstructor DOES work, so the object get's deconstructed when it exits Test()

    Read the article

  • [java] tcp socket communication [send and recieve help]

    - by raven
    hello, I am creating a Chat in java. I have a method (onMouseRelease) inside an object that creates a tcp server and waits for a socket ServerSocket server = new ServerSocket(port); Socket channel = server.accept(); now I want to make a thread that will loop and read data from the socket, so that once the user on the other side sent me a string, I will extract the data from the socket [or is it called packet? sry I am new to this], and update a textbox to add the additional string from the socket [or packet?]. I have no idea how to READ (extract) the information from the scoket [/packet] and then update it into a JTextArea which is called userOutput. And how to Send a string to the other client, so that it will also could read the new data and update its JTextArea. (from what I know, for a 2 sided tcp communication you need one computer to host a server and the other to connect [as a client] and once the connection is set the client can also recieve new information from the socket. Is that true? and please tell me how ) Any help appreciated !! I know this is abit long but I have searched allot and didn't understand [I saw something like printwriter but failed to understand].

    Read the article

  • Not getting an array as result (calling a webservice by AJAX-JSON)

    - by Pasargad
    I'm trying to get the result of my web service as an array and then loop over the result to fetch all of the data; what I have done so far: In my web service when I return the result I use return json_encode($newFiles); and the result is as following: "[{\"path\":\"c:\\\\my_images\\\\123.jpg\",\"ID\":\"123\",\"FName\":\"John\",\"LName\":\"Brown\",\"dept\":\"Hr\"}]" tehn in my Web application I'm calling the rest web service by the following code in the RestService class: public function getNewImages($time) { $url = $this->rest_url['MyService'] . "?action=getAllNewPhotos&accessKey=" . $this->rest_key['MyService'] . "&lastcheck=" . $time; $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, $url); curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); $data = curl_exec($ch); if ($data) { return json_decode($data); } else { return null; } } and then in my controller I have the following code: public function getNewImgs($time="2011-11-03 14:35:08") { $newImgs = $this->restservice->getNewImages($time); echo json_encode$newImgs; } and I'm calling this `enter code here`controller method by AJAX: $("#searchNewImgManually").click(function(e) { e.preventDefault(); $.ajax({ type: "POST", async: true, datatype: "json", url: "<?PHP echo base_url("myProjectController/getNewImgs"); ?>", success: function(imgsResults) { alert(imgsResults[0]); } }); }); but instead of giving me the first object it is just giving me quotation mark (the first charachter of the result) " Why is that? I'm passing in JSON format and in AJAX I mentioned datatype as "JSON" ! Please let me know if you need more clarification! Thanks :)

    Read the article

  • More efficient way to update multiple elements in javascript and/or jquery?

    - by Seiverence
    Say I have 6 divs with ID "#first", ""#second" ... "#sixth". Say if I wanted to execute functions on each of those divs, I would set up an array that contains each of the names of the divs I want to update as an element in the array of strings. ["first", "second", "third"] that I want to update. If I wanted to apply I function, I set up a for loop that iterates through each element in the array and say if I wanted to change the background color to red: function updateAllDivsInTheList() { for(var i = 0; i < array.size; i++) $("#"+array[i]).changeCssFunction(); } } Whenever I create a new div, i would add it to the array. The issue is, if I have a large number of divs that need to get updated, say if I wanted to update 1000 out of 1200 divs, it may be a pain/performance tank to have to sequentially iterate through every single element in the array. Is there some alternative more efficient way of updating multiple divs without having to sequentially iterate through every element in an array, maybe with some other more efficient data structure besides array? Or is what I am doing the most efficient way to do it? If can provide some example, that would be great.

    Read the article

  • Objective C - creating concrete class instances from base class depending upon type

    - by indiantroy
    Just to give a real world example, say the base class is Vehicle and concrete classes are TwoWheeler and FourWheeler. Now the type of the vehicle - TwoWheeler or FourWheeler, is decided by the base class Vehicle. When I create an instance of TwoWheeler/FourWheeler using alloc-init method, it calls the super implementation like below to set the value of common properties defined in the Vehicle class and out of these properties one of them is type that actually decides if the type is TwoWheeler or FourWheeler. if (self = [super initWithDictionary:dict]){ [self setOtherAttributes:dict]; return self; } Now when I get a collection of vehicles some of them could be TwoWheeler and others will be FourWheeler. Hence I cannot directly create an instance of TwoWheeler or FourWheeler like this Vehicle *v = [[TwoWheeler alloc] initWithDictionary:dict]; Is there any way I can create an instance of base class and once I know the type, create an instance of child class depending upon type and return it. With the current implementation, it would result in infinite loop because I call super implementation from concrete class. What would be the perfect design to handle this scenario when I don't know which concrete class should be instantiated beforehand?

    Read the article

  • Chat app vs REST app - use a thread in an Activity or a thread in a Service?

    - by synic
    In Virgil Dobjanschi's talk, "Developing Android REST client applications" (link here), he said a few things that took me by surprise. Including: Don't run http queries in threads spawned by your activities. Instead, communicate with a service to do them, and store the information in a ContentProvider. Use a ContentObserver to be notified of changes. Always perform long running tasks in a Service, never in your Activity. Stop your Service when you're done with it. I understand that he was talking about a REST API, but I'm trying to make it fit with some other ideas I've had for apps. One of APIs I've been using uses long-polling for their chat interface. There is a loop http queries, most of which will time out. This means that, as long as the app hasn't been killed by the OS, or the user hasn't specifically turned off the chat feature, I'll never be done with the Service, and it will stay open forever. This seems less than optimal. Long question short: For a chat application that uses long polling to simulate push and immediate response, is it still best practice to use a Service to perform the HTTP queries, and store the information in a ContentProvider?

    Read the article

  • Strange Puzzle - Invalid memory access of location

    - by Rob Graeber
    The error message I'm getting consistently is: Invalid memory access of location 0x8 rip=0x10cf4ab28 What I'm doing is making a basic stock backtesting system, that is iterating huge arrays of stocks/historical data across various algorithms, using java + eclipse on the latest Mac Os X. I tracked down the code that seems to be causing it. A method that is used to get the massive arrays of data and is called thousands of times. Nothing is retained so I don't think there is a memory leak. However there seems to be a set limit of around 7000 times I can iterate over it before I get the memory error. The weird thing is that it works perfectly in debug mode. Does anyone know what debug mode does differently in Eclipse? Giving the jvm more memory doesn't help, and it appears to work fine using -xint. And again it works perfectly in debug mode. public static List<Stock> getStockArray(ExchangeType e){ List<Stock> stockArray = new ArrayList<Stock>(); if(e == ExchangeType.ALL){ stockArray.addAll(getStockArray(ExchangeType.NYSE)); stockArray.addAll(getStockArray(ExchangeType.NASDAQ)); }else if(e == ExchangeType.ETF){ stockArray.addAll(etfStockArray); }else if(e == ExchangeType.NYSE){ stockArray.addAll(nyseStockArray); }else if(e == ExchangeType.NASDAQ){ stockArray.addAll(nasdaqStockArray); } return stockArray; } A simple loop like this, iterated over 1000s of times, will cause the memory error. But not in debug mode. for (Stock stock : StockDatabase.getStockArray(ExchangeType.ETF)) { System.out.println(stock.symbol); }

    Read the article

  • Why is it possible to enumerate a LinqToSql query after calling Dispose() on the DataContext?

    - by DanM
    I'm using the Repository Pattern with some LinqToSql objects. My repository objects all implement IDisposable, and the Dispose() method does only thing--calls Dispose() on the DataContext. Whenever I use a repository, I wrap it in a using person, like this: public IEnumerable<Person> SelectPersons() { using (var repository = _repositorySource.GetNew<Person>(dc => dc.Person)) { return repository.GetAll(); } } This method returns an IEnumerable<Person>, so if my understanding is correct, no querying of the database actually takes place until Enumerable<Person> is traversed (e.g., by converting it to a list or array or by using it in a foreach loop), as in this example: var persons = gateway.SelectPersons(); // Dispose() is fired here var personViewModels = ( from b in persons select new PersonViewModel { Id = b.Id, Name = b.Name, Age = b.Age, OrdersCount = b.Order.Count() }).ToList(); // executes queries In this example, Dispose() gets called immediately after setting persons, which is an IEnumerable<Person>, and that's the only time it gets called. So, a couple questions: How does this work? How can a disposed DataContext still query the database for results when I walk the IEnumerable<Person>? What does Dispose() actually do? I've heard that it is not necessary (e.g., see this question) to dispose of a DataContext, but my impression was that it's not a bad idea. Is there any reason not to dispose of it?

    Read the article

< Previous Page | 270 271 272 273 274 275 276 277 278 279 280 281  | Next Page >