Search Results

Search found 14532 results on 582 pages for 'dynamic types'.

Page 508/582 | < Previous Page | 504 505 506 507 508 509 510 511 512 513 514 515  | Next Page >

  • How do I populate an NSMutableArray in one class with another object?

    - by AngeloS
    Hello, I know this is a simple answer, but I can't seem to find the solution. I created an object in its own class and I am trying to populate it with data from another class. For simple data types like NSString, I have no problem, but when trying make an NSMutableArray equal to another NSMutableArray or when I try to populate a NSMutableArray with another objects (like strings), I keep getting exception errors... Here is the object I am trying to populate: #import <Foundation/Foundation.h> @interface RSSFeedList : NSObject { NSString *subject; NSMutableArray *rssfeedDetail; } @property (nonatomic, retain) NSString *subject; @property (nonatomic, retain) NSMutableArray *rssfeedDetail; @end This is how I was able to populate the NSString 'subject' in another class: rssFeedList.subject = @"test"; However, if I follow similar convention within that same class with respect to an Array, it throws an exception: rssFeedList.rssfeedDetail = rssItemDetailArray; Where rssItemDetailArray is a NSMutableArray that I have built in the same class. I have also tried to add items (i tried strings for testing) to the NSMutableArray directly like so to no avail: [rssFeedList.rssfeedDetail addObject:@"test"]; Any ideas?? Thanks in advance!!

    Read the article

  • in haskell, why do I need to specify type constraints, why can't the compiler figure them out?

    - by Steve
    Consider the function, add a b = a + b This works: *Main> add 1 2 3 However, if I add a type signature specifying that I want to add things of the same type: add :: a -> a -> a add a b = a + b I get an error: test.hs:3:10: Could not deduce (Num a) from the context () arising from a use of `+' at test.hs:3:10-14 Possible fix: add (Num a) to the context of the type signature for `add' In the expression: a + b In the definition of `add': add a b = a + b So GHC clearly can deduce that I need the Num type constraint, since it just told me: add :: Num a => a -> a -> a add a b = a + b Works. Why does GHC require me to add the type constraint? If I'm doing generic programming, why can't it just work for anything that knows how to use the + operator? In C++ template programming, you can do this easily: #include <string> #include <cstdio> using namespace std; template<typename T> T add(T a, T b) { return a + b; } int main() { printf("%d, %f, %s\n", add(1, 2), add(1.0, 3.4), add(string("foo"), string("bar")).c_str()); return 0; } The compiler figures out the types of the arguments to add and generates a version of the function for that type. There seems to be a fundamental difference in Haskell's approach, can you describe it, and discuss the trade-offs? It seems to me like it would be resolved if GHC simply filled in the type constraint for me, since it obviously decided it was needed. Still, why the type constraint at all? Why not just compile successfully as long as the function is only used in a valid context where the arguments are in Num? Thank you.

    Read the article

  • Detect that the onscreen keyboard has been displayed on Windows Phone 7

    - by David_001
    Simple question: How do I detect that the onscreen keyboard has been displayed on windows mobile 7? Is there an event I can add a listener to? It takes up about half the screen and I want to scroll the view up when it gets displayed... EDIT: A comment below indicates more clearly what I'm trying to do: I have a textbox input, and as the user types into it an autocomplete dropdown appears below it (like google suggest). By default, the active control (the textbox) scrolls into view when focussed, and the onscreen keyboard is directly below it. The onscreen keyboard appears in front of my autocomplete dropdown - what I want to do is make the screen scroll a little further up, so there's some room for my dropdown to be shown. The windows phone UI design guidelines say: "When the keyboard is deployed, the application should scroll to ensure the active edit control and the caret are in view". This happens fine, it's just the non-active dropdown gets hidden behind the onscreen keyboard. The guidelines also say that an application can choose to show the onscreen keyboard, and can also choose to close it. At the moment i'm stuck, and I don't think (based on my research and the replies to this question) that it's possible to detect that the onscreen keyboard has been displayed. I'm moving my investigation to see if it's possible to determine the "visible area" of the page (width & height in pixels for example), and combine this with an onfocus for the textbox... not sure if this will prove fruitful though.

    Read the article

  • refactoring my code. My headers (Header Guard Issues)

    - by numerical25
    I had a post similar to this awhile ago based on a error I was getting. I was able to fix it but since then I been having trouble doing things because headers keep blocking other headers from using code. Honestly, these headers are confusing me and if anyone has any resources that will address these types of issues, that will be helpful. What I essentially want to do is be able to have rModel.h be included inside RenderEngine.h. every time I add rModel.h to RenderEngine.h, rModel.h is no longer able to use RenderEngine.h. (rModel.h has a #include of RenderEngine.h as well). So in a nutshell, RenderEngine and rModel need to use each others functionalities. On top of all this confusion, the Main.cpp needs to use RenderEngine. stdafx.h #include "targetver.h" #define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers // Windows Header Files: #include <windows.h> // C RunTime Header Files #include <stdlib.h> #include <malloc.h> #include <memory.h> #include <tchar.h> #include "resource.h" main.cpp #include "stdafx.h" #include "RenderEngine.h" #include "rModel.h" // Global Variables: RenderEngine go; rModel *g_pModel; ...code........... rModel.h #ifndef _MODEL_H #define _MODEL_H #include "stdafx.h" #include <vector> #include <string> #include "rTri.h" #include "RenderEngine.h" ........Code RenderEngine.h #pragma once #include "stdafx.h" #include "d3d10.h" #include "d3dx10.h" #include "dinput.h" #include "rModel.h" .......Code......

    Read the article

  • Is there a Java data structure that is effectively an ArrayList with double indicies and built-in in

    - by Bob Cross
    I am looking for a pre-built Java data structure with the following characteristics: It should look something like an ArrayList but should allow indexing via double-precision rather than integers. Note that this means that it's likely that you'll see indicies that don't line up with the original data points (i.e., asking for the value that corresponds to key "1.5"). As a consequence, the value returned will likely be interpolated. For example, if the key is 1.5, the value returned could be the average of the value at key 1.0 and the value at key 2.0. The keys will be sorted but the values are not ensured to be monotonically increasing. In fact, there's no assurance that the first derivative of the values will be continuous (making it a poor fit for certain types of splines). Freely available code only, please. For clarity, I know how to write such a thing. In fact, we already have an implementation of this and some related data structures in legacy code that I want to replace due to some performance and coding issues. What I'm trying to avoid is spending a lot of time rolling my own solution when there might already be such a thing in the JDK, Apache Commons or another standard library. Frankly, that's exactly the approach that got this legacy code into the situation that it's in right now.... Is there such a thing out there in a freely available library?

    Read the article

  • Why do we need serialization in web service

    - by Cloud2010
    I have one webservice: public class Product { public int ProductId { get; set; } public string ProductName { get; set; } } public class Service : System.Web.Services.WebService { public Service () { //Uncomment the following line if using designed components //InitializeComponent(); } [WebMethod] public List<Product> GetItems() { List<Product> productList = new List<Product>() { new Product{ProductId=1,ProductName="Pencil"}, new Product{ProductId=2,ProductName="Pen"} }; return productList; } and in a asp.net application I am consuming it like: localhost.Service s = new localhost.Service(); List<localhost.Product> k = new List<localhost.Product>(); k = s.GetItems().ToList(); // i am getting the values here. now my question is do I need to serialize my webmethod as i am returning custom types? when should we serialize ? is it necessary at all, if yes , then what are the conditions?

    Read the article

  • Most Efficient way to deal with multiple CCSprites?

    - by nardsurfer
    I have four different types of objects within my environment(box2d), each type of object having multiple instances of itself, and would like to find the most efficient way to deal with adding and manipulating all the CCSprites. The sprites are all from different files, so would it be best to create each sprite and add it to a data structure (NSMutableArray) or would I use a CCSpriteBatchNode even though each CCSprite file is different (for each type of object)? Thanks. @interface LevelScene : CCLayer { b2World* world; GLESDebugDraw *m_debugDraw; CCSpriteBatchNode *ballBatch; CCSpriteBatchNode *blockBatch; CCSpriteBatchNode *springBatch; CCSprite *goal; } +(id) scene; // adds a new sprite at a given coordinate -(void) addNewBallWithCoords:(CGPoint)p; // loads the objects (blocks, springs, and the goal), returns the Level Object -(Level) loadLevel:(int)level; @end or using NSMutableArray objects within the Level object... @interface zLevel : zThing { NSMutableArray *springs; NSMutableArray *blocks; NSMutableArray *balls; zGoal *goal; int levelNumber; } @property(nonatomic,retain)NSMutableArray *springs; @property(nonatomic,retain)NSMutableArray *blocks; @property(nonatomic,retain)NSMutableArray *balls; @property(nonatomic,retain)zGoal *goal; @property(nonatomic,assign)int levelNumber; -(void)initWithLevel:(int)level; -(void)loadLevelThings; @end

    Read the article

  • How to get a category listing from Magento?

    - by alex
    I want to create a page in Magento that shows a visual representation of the categories.. example CATEGORY product 1 product 2 ANOTHER CATEGORY product 3 My problem is, their database is organised very differently to what I've seen in the past. They have tables dedicated to data types like varchar, int, etc. I assume this is for performance or similiar. I haven't found a way to use MySQL to query the database and get a list of categories. I'd then like to match these categories to products, to get a listing of products for each category. Unfortunately Magento seems to make this very difficult. Also I have not found a method that will work from within a page block.. I have created showcase.phtml and put it in the XML layout and it displays and runs it's PHP code. I was hoping for something easy like looping through $this-getAllCategories(); and then a nested loop inside with something like $category-getChildProducts(); Can anyone help me? Thank you!

    Read the article

  • How should I map an abstract class with simple xml in Java?

    - by spderosso
    Hi, I want to achieve the following xml using simple xml framework (http://simple.sourceforge.net/): <events> <course-added date="01/01/2010"> ... </course-added> <course-removed date="01/02/2010"> .... </course-removed> <student-enrolled date="01/02/2010"> ... </student-enrolled> </events> I have the following (but it doesn't achieve the desired xml): @Root(name="events") class XMLEvents { @ElementList(inline=true) ArrayList<XMLEvent> events = Lists.newArrayList(); ... } abstract class XMLEvent { @Attribute(name="date") String dateOfEventFormatted; ... } And different type of XMLNodes that have different information (but are all different types of events) @Root(name="course-added") class XMLCourseAdded extends XMLEvent{ @Element(name="course") XMLCourseLongFormat course; .... } @Root(name="course-removed") class XMLCourseRemoved extends XMLEvent { @Element(name="course-id") String courseId; ... } How should I do the mapping or what should I change in order to be able to achieve de desired xml? Thanks!

    Read the article

  • Returning JSON or XML for Exceptions in Jersey

    - by Dominic
    My goal is to have an error bean returned on a 404 with a descriptive message when a object is not found, and return the same MIME type that was requested. I have a look up resource, which will return the specified object in XML or JSON based on the URI (I have setup the com.sun.jersey.config.property.resourceConfigClass servlet parameter so I dont need the Accept header. My JAXBContextResolver has the ErrorBean.class in its list of types, and the correct JAXBContext is returned for this class because I can see in the logs). eg: http://foobar.com/rest/locations/1.json @GET @Path("{id}") @Produces({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML}) public Location getCustomer(@PathParam("id") int cId) { //look up location from datastore .... if (location == null) { throw new NotFoundException("Location" + cId + " is not found"); } } And my NotFoundException looks like this: public class NotFoundException extends WebApplicationException { public NotFoundException(String message) { super(Response.status(Response.Status.NOT_FOUND). entity(new ErrorBean( message, Response.Status.NOT_FOUND.getStatusCode() ) .build()); } } The ErrorBean is as follows: @XmlRootElement(name = "error") public class ErrorBean { private String errorMsg; private int errorCode; //no-arg constructor, property constructor, getter and setters ... } However, I'm always getting a 204 No Content response when I try this. I have hacked around, and if I return a string and specify the mime type this works fine: public NotFoundException(String message) { super(Response.status(Response.Status.NOT_FOUND). entity(message).type("text/plain").build()); } I have also tried returning an ErrorBean as a resource. This works fine: {"errorCode":404,"errorMsg":"Location 1 is not found!"}

    Read the article

  • How to make restrictions on XML Schema Complex type?

    - by chobo2
    Hi I am reading the tutorials on w3cschools ( http://www.w3schools.com/schema/schema_complex.asp ) but they don't seem to mention how you could add restrictions on complex types. Like for instance I have this schema. <xs:element name="employee"> <xs:complexType> <xs:sequence> <xs:element name="firstname" type="xs:string"/> <xs:element name="lastname" type="xs:string"/> </xs:sequence> </xs:complexType> </xs:element> now I want to make sure the firstname is no more then 10 characters long. How do I do this? I tried to put in the simple type for the firstname but it says I can't do that since I am using a complex type. So how do I put restrictions like that on the file so the people who I give the schema to don't try to make the firstname 100 characters.

    Read the article

  • Python server open all ports

    - by user1670178
    I am trying to open all ports using this code, why can I not create a loop to perform this function? http://www.kellbot.com/2010/02/tutorial-writing-a-tcp-server-in-python/ #!/usr/bin/python # This is server.py file ##server.py from socket import * #import the socket library n=1025 while n<1050: ##let's set up some constants HOST = '' #we are the host PORT = n #arbitrary port not currently in use ADDR = (HOST,PORT) #we need a tuple for the address BUFSIZE = 4096 #reasonably sized buffer for data ## now we create a new socket object (serv) ## see the python docs for more information on the socket types/flags serv = socket( AF_INET,SOCK_STREAM) ##bind our socket to the address serv.bind((ADDR)) #the double parens are to create a tuple with one element serv.listen(5) #5 is the maximum number of queued connections we'll allow serv = socket( AF_INET,SOCK_STREAM) ##bind our socket to the address serv.bind((ADDR)) #the double parens are to create a tuple with one element serv.listen(5) #5 is the maximum number of queued connections we'll allow print 'listening...' n=n+1 conn,addr = serv.accept() #accept the connection print '...connected!' conn.send('TEST') conn.close() How do I make this work so that I can specify input range and have the server open all ports up to 65535? #!/usr/bin/python # This is server.py file from socket import * #import the socket library startingPort=input("\nPlease enter starting port: ") startingPort=int(startingPort) #print startingPort def connection(): ## let's set up some constants HOST = '' #we are the host PORT = startingPort #arbitrary port not currently in use ADDR = (HOST,PORT) #we need a tuple for the address BUFSIZE = 4096 #reasonably sized buffer for data def socketObject(): ## now we create a new socket object (serv) serv = socket( AF_INET,SOCK_STREAM) def bind(): ## bind our socket to the address serv = socket( AF_INET,SOCK_STREAM) serv.bind((ADDR)) #the double parens are to create a tuple with one element serv.listen(5) #5 is the maximum number of queued connections we'll allow serv = socket( AF_INET,SOCK_STREAM) print 'listening...' def accept(): conn,addr = serv.accept() #accept the connection print '...connected!' conn.send('TEST') def close(): conn.close() ## Main while startingPort<65535: connection() socketObject() bind() accept() startingPort=startingPort+1

    Read the article

  • getting string.substring(N) not to choke when N > string.length

    - by aape
    I'm writing some code that takes a report from the mainframe and converts it to a spreadsheet. They can't edit the code on the MF to give me a delimited file, so I'm stuck dealing with it as fixed width. It's working okay now, but I need to get it more stable before I release it for testing. My problem is that in any given line of data, say it could have three columns of numbers, each five chars wide at positions 10, 16, and 22. If on this one particular row, there's no data for the last two cols, it won't be padded with spaces; rather, the length of the string will be only 14. So, I can't just blindly have dim s as string = someStream.readline a = s.substring(10, 5) b = s.substring(16, 5) c = s.substring(22, 5) because it'll choke when it substrings past the length of the string. I know I could test the length of the string before processing each row, and I have automated the filling of some of the vsariables using a counter and a loop, and using the counter*theWidthOfTheGivenVariable to jump around, but this project was a dog to start with (come on! turning a report into a spreadsheet?), but there are many different types of rows (it's not just a grid), and the code's getting ugly fast. I'd like this to be clean, clear, and maintainable for the poor sucker that gets this after me. If it matters, here's my code so far (it's really crufty at the moment). You can see some of my/its idiocy in the processSection#data subs So, I'm wondering 1) is there a way baked in to .NET to have string.substring not error when reading past the end of a string without wrapping it in a try...catch? and 2) would it be appropriate in this situation to write a new string class that inherits from string that has a more friendly substring function in it? ETA: Thanks for all the advice and knowledge everyone. I'll go with the extension. Hopefully one of these years, I'll get my chops up enough to pay someone back in kind. :)

    Read the article

  • Design Advice Needed For Synonyms Database

    - by James J
    I'm planning to put together a database that can be used to query synonyms of words. The database will end up huge, so the idea is to keep things running fast. I've been thinking about how to do this, but my database design skills are not up to scratch these days. My initial idea was to have each word stored in one table, and then another table with a 1 to many relationship where each word can be linked to another word and that table can be queried. The application I'm developing allows users to highlight a word, and then type in, or select some synonyms from the database for that word. The application learns from the user input so if someone highlights "car" and types in "motor" the database would be updated to link the relationship if it don't exist already. What I don't want to happen is for a user to type in the word "shop" and link it to the word car. So I'm thinking I will need to add some sort of weight to each relationship. Eventually the synonyms the users enter will be used so they can auto select common synonyms used with a certain word. The lower weight words will not be displayed so shop could never be a synonym of car unless it had a very high weight, and chances are nobody is going to do that. Does the above sound right? Can you offer any suggestions or improvements?

    Read the article

  • C++ universal data type

    - by Gokul
    I have a universal data type, which is passed by value, but does not maintain the type information. We store only pointers and basic data types(like int, float etc) inside this. Now for the first time, we need to store std::string inside this. So we decided to convert it into std::string* and store it. Then comes the problem of destruction. We don't like to copy the std::string every time. So i am thinking of an approach like this. Say the data type looks like this class Atom { public : enum flags { IS_STRING, IS_EMPTY, HAS_GOT_COPIED, MARKER }; private: void* m_value; std::bitset<MARKER> m_flags; public: ..... Atom( Atom& atm ) { atm.m_flags.set( HAS_GOT_COPIED ); ..... } ..... ~Atom() { if( m_flags.test(IS_STRING) && !m_flags.test(HAS_GOT_COPIED) ) { std::string* val = static_cast<std::string*>(m_value); delete val; } } }; Is this a good approach to find out whether there is no more reference to std::string*? Any comments.. Thanks, Gokul.

    Read the article

  • "Find all tiles connected to this one" project

    - by Omega
    Remember MS Paint? The bucket tool? If you used it and clicked on a pixel, all pixels connected to this pixel that are the same are affected. The theory is, I suppose, to check if there is any pixel adjacent to the selected one. If such pixel is the same type as the selected one, check for more adjacent pixels in this one, and so on. I want to implement something similar in VB.NET. Basically I have a 2D array map which represents the map. Let's assume there are only two types of tile: 0 and 1. Now, I got pretty much everything ready: I got my 2d map and I can tell which tile is clicked and tell what array indexes are the ones that represent such tile. Now for the "painting" process. Whenever I think about it, I can't figure a convenient way to execute such iteration. Can someone help me choosing a correct design/way/tip to achieve this?

    Read the article

  • Is this a good way to generically deserialize objects?

    - by Damien Wildfire
    I have a stream onto which serialized objects representing messages are dumped periodically. The objects are one of a very limited number of types, and other than the actual sequence of bytes that arrives, I have no way of knowing what type of message it is. I would like to simply try to deserialize it as an object of a particular type, and if an exception is thrown, try again with the next type. I have an interface that looks like this: public interface IMessageHandler<T> where T : class, IMessage { T Handle(string message); } // elsewhere: // (These are all xsd.exe-generated classes from an XML schema.) public class AppleMessage : IMessage { ... } public class BananaMessage : IMessage { ... } public class CoconutMessage : IMessage { ... } Then I wrote a GenericHandler<T> that looks like this: public class GenericHandler<T> : IMessageHandler<T> where T: class, IMessage { public class MessageHandler : IMessageHandler { T IMessageHandler.Handle(string message) { T result = default(T); try { // This utility method tries to deserialize the object with an // XmlSerializer as if it were an object of type T. result = Utils.SerializationHelper.Deserialize<T>(message); } catch (InvalidCastException e) { result = default(T); } return result; } } } Two questions: Using my GenericHandler<T> (or something similar to it), I'd now like to populate a collection with handlers that each handle a different type. Then I want to invoke each handler's Handle method on a particular message to see if it can be deserialized. If I get a null result, move onto the next handler; otherwise, the message has been deserialized. Can this be done? Is there a better way to deserialize data of unknown (but restricted) type?

    Read the article

  • Getting the current item number or index when using will_paginate in rails app

    - by Rich
    I have a rails app that stores movies watched, books read, etc. The index page for each type lists paged collections of all its items, using will_paginate to bring back 50 items per page. When I output the items I want to display a number to indicate what item in the total collection it is. The numbering should be reversed as the collection is displayed with most recent first. This might not relate to will_paginate but rather some other method of calculation. I will be using the same ordering in multiple types so it will need to be reusable. As an example, say I have 51 movies. The first item of the first page should display: Fight Club - Watched: 30th Dec 2010 Whilst the last item on the page should display: The Matrix - Watched: 3rd Jan 2010 The paged collection is available as an instance variable e.g. @movies, and @movies.count will display the number of items in the paged collection. So if we're on page 1, movies.count == 50, whilst on page 2 @movies.count == 1. Using Movie.count would give 51. If the page number and page size can be accessed the number could be calculated so how can they be returned? Though I'm hopeful there is something that already exists to handle this calculation!

    Read the article

  • Difference between the address space of parent process and its child process in Linux?

    - by abbas1707
    Hi, I am confused about it. I have read that when a child is created by a parent process, child gets a copy of its parent's address space. What it means here by copy? If i use code below, then it prints same addresses of variable 'a' which is on heap in all cases. i.e in case of child and parent. So what is happening here? #include <sys/types.h> #include <stdio.h> #include <unistd.h> #include <stdlib.h> int main () { pid_t pid; int *a = (int *)malloc(4); printf ("heap pointer %p\n", a); pid = fork(); if (pid < 0) { fprintf (stderr, "Fork Failed"); exit(-1); } else if (pid == 0) { printf ("Child\n"); printf ("in child heap pointer %p\n", a); } else { wait (NULL); printf ("Child Complete\n"); printf ("in parent heap pointer %p\n", a); exit(0); } }

    Read the article

  • How do I split ONE array to two separate arrays based on magnitude size and a threshold?

    - by youhaveaBigego
    I have an array which has BIG numbers and small numbers in it. I got it from after running a log from WireShark. It is the total number of Bytes of TCP traffic. But Wireshark does not discriminate(it would actually try, and hence it will tell you the traffic stats of ALL types of traffic, but since This is how the Array look like : @Array=qw(10912980 10924534 10913356 10910304 10920426 10900658 10911266 10912088 10928972 10914718 10920770 10897774 10934258 10882186 10874126 8531 8217 3876 8147 8019 68157 3432 3350 3338 3280 3280 7845 7869 3072 3002 2828 8397 1328 1280 1240 1194 1193 1192 1194 6440 1148 1218 4236 1161 1100 1102 1148 1172 6305 1010 5437 3534 4623 4669 3617 4234 959 1121 1121 1075 3122 3076 1020 3030 628 2938 2938 1611 1611 1541 1541 1541 1541 1541 1541 1541 1541 1541 1541 1541 1541 583 370 178) When you look at these this array carefully, one thing is obvious to the human eye. There are really BIG numbers and small numbers. (Basically what I am saying is, there is the 1% class and low income class, no middle class). I want to split the array to two different arrays. That would require me to set a threshold. Array 1 should be ONLY the BIG numbers (10924534-10874126), and array 2 should be the smaller numbers (68157-178). Btw, the array is not sorted. User will NOT input the threshold, and hence should be determined smartly.

    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

  • casting char[][] to char** causes segfault?

    - by Earlz
    Ok my C is a bit rusty but I figured I'd make my next(small) project in C so I could polish back up on it and less than 20 lines in I already have a seg fault. This is my complete code: #define ROWS 4 #define COLS 4 char main_map[ROWS][COLS+1]={ "a.bb", "a.c.", "adc.", ".dc."}; void print_map(char** map){ int i; for(i=0;i<ROWS;i++){ puts(map[i]); //segfault here } } int main(){ print_map(main_map); //if I comment out this line it will work. puts(main_map[3]); return 0; } I am completely confused as to how this is causing a segfault. What is happening when casting from [][] to **!? That is the only warning I get. rushhour.c:23:3: warning: passing argument 1 of ‘print_map’ from incompatible pointer type rushhour.c:13:7: note: expected ‘char **’ but argument is of type ‘char (*)[5]’ Are [][] and ** really not compatible pointer types? They seem like they are just syntax to me.

    Read the article

  • VB.NET Button Issue

    - by Michael
    I am having problem with a button the code of my button is. Private Sub btnCalculateCosts_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculateCosts.Click it handles: ' This Calculate Costs button click event handler edits the ' registration(costs) form to ensure it contains valid data. ' Then, after passing control to the business class, it ' displays the registration cost. Dim objCourse As Course Dim objCourseCostsFile As Course Dim InputError As Boolean = False ' Is student ID entered properly If Me.txtCorporateID.MaskFull = False Then MessageBox.Show("Enter your Corporate ID in the Corporate ID box", _ "Error") Me.txtCorporateID.Clear() Me.txtCorporateID.Focus() InputError = True ' Is student name entered properly ElseIf Me.txtFirstName.TextLength < 1 Or _ Me.txtFirstName.Text < "A" Then MessageBox.Show("Please enter your first name in the First Name box", "Error") Me.txtFirstName.Clear() Me.txtFirstName.Focus() InputError = True ' Is number of units entered properly ElseIf Me.txtLastName.TextLength < 1 Or _ Me.txtLastName.Text < "A" Then MessageBox.Show("Please enter your last name in the Last Name box", "Error") Me.txtLastName.Clear() Me.txtLastName.Focus() InputError = True ' Is number of units entered properly ElseIf Not IsNumeric(Me.txtNumberOfDays.Text) Then MessageBox.Show("Enter the units in the Number of Units box", _ "Error") Me.txtNumberOfDays.Clear() Me.txtNumberOfDays.Focus() InputError = True ' Has 1-4 units been entered ElseIf Convert.ToInt32(Me.txtNumberOfDays.Text) < 1 _ Or Convert.ToInt32(Me.txtNumberOfDays.Text) > 4 Then MessageBox.Show("Units must be 1 - 4", "Error") Me.txtNumberOfDays.Clear() Me.txtNumberOfDays.Focus() InputError = True End If ' If no input error, process the registration costs If Not InputError Then If Me.radPreConferenceCourse.Checked = False Then objCourse = New Course(txtCorporateID.Text, txtFirstName.Text, txtLastName.Text, txtNumberOfDays.Text) Me.lblCosts.Visible = True Me.lblCosts.Text = "Total Conference Costs Are: " _ & (objCourse.ComputeCosts()).ToString("C2") Else objCourse = New Course(txtCorporateID.Text, txtFirstName.Text, txtLastName.Text, txtNumberOfDays.Text, g) Me.lblCosts.Visible = True Me.lblCosts.Text = "Total Conference Costs Are: " _ & (objCourse.ComputeCosts()).ToString("C2") Receiving the error: Handles clause requrieres a WithEvents variable defined in the containing type or one of its base types.

    Read the article

  • How to check of which user-defined type a current JSON element is during $.each()?

    - by Bob
    I have the following structure for a JSON file: ({condos:[{Address:'123 Fake St.', Lat:'56.645654', Lng:'23.534546'},{... another condo ...},{...}],houses:[{Address:'1 Main Ave.', Lat:'34.765766', Lng:'27.8786674'},{... another house ...}, {...}]}) So, I have a list of condos and houses in one big JSON array. I want to plot them all on my map, but I want to give condos and houses different marker icons( blue marker for condos, green marker for houses ). Problem I have is - figuring out how to distinguish between types of markers when I $.each() through them. How would I use if to check whether I'm working with a condo or a house at the moment? var markers = null; $('#map').gmap(mapOptions).bind('init', function(){ $.post('getMarkers.php', function(json){ markers = json; $.each(markers, function(type, dataMembers) { $.each(dataMembers, function(i, j){ //if house use house.png to create marker $('#map').gmap('addMarker', { 'position': new google.maps.LatLng(parseFloat(Lat), parseFloat(Lng)), 'bounds':true, 'icon':'house.png' } ); //if condo use condo.png $('#map').gmap('addMarker', { 'position': new google.maps.LatLng(parseFloat(Lat), parseFloat(Lng)), 'bounds':true, 'icon':'condo.png' } ); }); }); }); });

    Read the article

  • Passing a string to a function in C++

    - by Chef Flambe
    I want to pass a string like "Celcius" into a function that I have but I keep getting errors tossed back at me from the Function. System::Console::WriteLine' : none of the 19 overloads could convert all the argument types I figure I just have something simple wrong. Can someone point out my mistake please? Using MS Visual C++ 2010 I've posted the offending code. The other functions (not posted) work fine. void PrintResult( double result, std::string sType ); // Print result and string // to the console //============================================================================================= // start of main //============================================================================================= void main( void ) { ConsoleKeyInfo CFM; // Program Title and Description ProgramDescription(); // Menu Selection and calls to data retrieval/calculation/result Print CFM=ChooseFromMenu(); switch(CFM.KeyChar) // ************************************************************ { //* case '1' : PrintResult(F2C(GetTemperature()),"Celsius"); //* break; //* //* case '2' : PrintResult(C2F(GetTemperature()),"Fahrenheit"); //* break; //* //* default : Console::Write("\n\nSwitch : Case !!!FAILURE!!!"); //* } //************************************************************ system("pause"); return; } //Function void PrintResult( double result, std::string sType ) { Console::WriteLine("\n\nThe converted temperature is {0:F2} degrees {1}\n\n",result,sType); return; }

    Read the article

< Previous Page | 504 505 506 507 508 509 510 511 512 513 514 515  | Next Page >