Search Results

Search found 54446 results on 2178 pages for 'struct vs class'.

Page 49/2178 | < Previous Page | 45 46 47 48 49 50 51 52 53 54 55 56  | Next Page >

  • Can C/C++ compiler report struct member offset

    - by Chen Jun
    Hello, everyone. I'd like to ask, can compiler(e.g. Visual C++) generate a report(.txt) telling struct member offset for a struct/all structs? If so, it helps debugging quite a lot. For example, when you read disassembler code in the debugger, it can be easier to associate an offset value to a struct member. Also, it is better to have compiler report offset of each local variable on a function stack frame(e.g. the offset relative to ebp on an X86 machine). Thank you in advance.

    Read the article

  • basic json > struct question

    - by danwoods
    I'm working with twitter's api, trying to get the json data from http://search.twitter.com/trends/current.json which looks like: {"as_of":1268069036,"trends":{"2010-03-08 17:23:56":[{"name":"Happy Women's Day","query":"\"Happy Women's Day\" OR \"Women's Day\""},{"name":"#MusicMonday","query":"#MusicMonday"},{"name":"#MM","query":"#MM"},{"name":"Oscars","query":"Oscars OR #oscars"},{"name":"#nooffense","query":"#nooffense"},{"name":"Hurt Locker","query":"\"Hurt Locker\""},{"name":"Justin Bieber","query":"\"Justin Bieber\""},{"name":"Cmon","query":"Cmon"},{"name":"My World 2","query":"\"My World 2\""},{"name":"Sandra Bullock","query":"\"Sandra Bullock\""}]}} My structs look like: type trend struct { name string query string } type trends struct { id string arr_of_trends []trend } type Trending struct { as_of string trends_obj trends } and then I parse the JSON into a variable of type Trending. I'm very new to JSON so my main concern is making sure I've have the data structure correctly setup to hold the returned json data. I'm writing this in 'Go' for a project for school. (This is not part of a particular assignment, just something I'm demo-ing for a presentation on the language)

    Read the article

  • how to specify which child class this object belong to after retrieving from a hashmap?

    - by chandra wibowo
    hi everyone, i have a parent class called Course, and two child class PostgradCourse and UndergradCourse. i have a hashmap HashMap courses; i store all the postgradCourse and undergradCourse objects in the hashmap. i want to retrieve an undergradCourse object from the hashmap using the key. Course course = courses.get(courseCode); then i want to call a method in the UndergradCourse class, setUnits() method course.setUnits(); but the compiler say cannot find symbol- method setUnit() im pretty sure the problem is the compiler is looking for a method setUnit() in the Course class instead of UndergradCourse class i did this but its not working UndergradCourse course = courses.get(courseCode); results in incompatible type so how can i retrieve undergradCourse object from the hashmap as an undergradCourse object instead of course object? so then i can call a method inside the child class thanks in advance

    Read the article

  • Why isn't this simple test class's method inherited in Ruby?

    - by Kevin Bannister
    Consider this very simple logging class: class MockLog def self.log_stub_method(*args) args.each do |a| define_method "#{a}" do |msg| t = Time.now.strftime("%Y-%m-%d %H:%M:%S") $stderr.puts "[#{a.upcase}] \u00bb [#{t}] #{msg}" end end end log_stub_method :fatal, :error, :warn, :info, :debug end Let's add logging to all our classes: class Module def has_logging() class_eval { @log = MockLog.new def log self.class.instance_variable_get :@log end } end end Now, why doesn't this work? class Foo has_logging end Foo.new.log.nil? # => false, as expected class Bar < Foo end Bar.new.log.nil? # => true?! Why wasn't the `log` method inherited?

    Read the article

  • c struct map to ruby using SWIG

    - by pierr
    Hi, Is there any body can confirm the description here is true? My experience is that I can not use Example::Vector.new at all. C/C++ structs are wrapped as Ruby classes, with accessor methods (i.e. "getters" and "setters") for all of the struct members. For example, this struct declaration: struct Vector { double x, y; }; gets wrapped as a Vector class, with Ruby instance methods x, x=, y and y=. These methods can be used to access structure data from Ruby as follows: $ irb irb(main):001:0> require 'Example' true irb(main):002:0> f = Example::Vector.new #<Example::Vector:0x4020b268> irb(main):003:0> f.x = 10 nil irb(main):004:0> f.x 10.0

    Read the article

  • Allocating memory in char * struct

    - by mrblippy
    hi, im trying to read in a word from a user, then dynamically allocate memory for the word and store it in a struct array that contains a char *. i keep getting a implicit declaration of function âstrlenâ so i know im going wrong somewhere. struct class { char class_code[7]; char *name; }; char buffer[101]; struct unit units[1000]; scanf("%s", buffer); units[0].name = (char *) malloc(strlen(buffer)+1); strcpy(units[0].name, buffer);

    Read the article

  • XML Outputting - PHP vs JS vs Anything Else?

    - by itsphil
    Hi everyone, I am working on developing a Travel website which uses XML API's to get the data. However i am relatively new to XML and outputting it. I have been experimenting with using PHP to output a test XML file, but currently the furthest iv got is to only output a few records. As it the questions states i need to know which technology will be best for this project. Below iv included some points to take into consideration. The website is going to be a large sized, heavy traffic site (expedia/lastminute size) My skillset is PHP (intermediate/high skilled) & Javascript (intermediate/high skilled) Below is an example of the XML that the API is outputting: <?xml version="1.0"?> <response method="###" success="Y"> <errors> </errors> <request> <auth password="test" username="test" /> <method action="###" sitename="###" /> </request> <results> <line id="6" logourl="###" name="Line 1" smalllogourl="###"> <ships> <ship id="16" name="Ship 1" /> <ship id="453" name="Ship 2" /> <ship id="468" name="Ship 3" /> <ship id="356" name="Ship 4" /> </ships> </line> <line id="63" logourl="###" name="Line 2" smalllogourl="###"> <ships> <ship id="492" name="Ship 1" /> <ship id="454" name="Ship 2" /> <ship id="455" name="Ship 3" /> <ship id="421" name="Ship 4" /> <ship id="401" name="Ship 5" /> <ship id="404" name="Ship 6" /> <ship id="405" name="Ship 7" /> <ship id="406" name="Ship 8" /> <ship id="407" name="Ship 9" /> <ship id="408" name="Ship 10" /> </ships> </line> <line id="41" logourl="###"> <ships> <ship id="229" name="Ship 1" /> <ship id="230" name="Ship 2" /> <ship id="231" name="Ship 3" /> <ship id="445" name="Ship 4" /> <ship id="570" name="Ship 5" /> <ship id="571" name="Ship 6" /> </ships> </line> </results> </response> If possible when suggesting which technlogy is best for this project, if you could provide some getting started guides or any information would be very much appreciated. Thank you for taking the time to read this.

    Read the article

  • c# 3.5 class List<int> class initialisation

    - by josephj1989
    I can initialize a List like new List{1,2,3,4,5}; However List does not have a constructor which accepts a single parameter. So I tried to run this through the debugger and it seems to be calling the Add method. So how does the compiler know which method to invoke to add each individual element. This may be a silly question but I am a bit confused. Thanks

    Read the article

  • Allocating memory for a char pointer that is part of a struct

    - by mrblippy
    hi, im trying to read in a word from a user, then dynamically allocate memory for the word and store it in a struct array that contains a char *. i keep getting a implicit declaration of function âstrlenâ so i know im going wrong somewhere. struct class { char class_code[4]; char *name; }; char buffer[101]; struct unit units[1000]; scanf("%s", buffer); units[0].name = (char *) malloc(strlen(buffer)+1); strcpy(units[0].name, buffer);

    Read the article

  • Memory error, access violation.

    - by Ordo
    Hello! I'm learning C on my own and as a exercise i have written a program but it does not work. The program is splitted into 3 parts. A header file, a main file for executing the program a file to define the functions. I'm not using all the functions yet but that shouldn't be the problem. Here is my header file, nothing special in it. #ifndef EMPLOYEE_H #define EMPLOYEE_H struct Employee { char first[21]; char last[21]; char title[21]; int salary; }; struct Employee* createEmployee(char*, char*, char*, int); // Creates a struct Employee object on the heap. char* getfirstname (struct Employee*); char* getlastname (struct Employee*); char* gettitle (struct Employee*); int getsalary (struct Employee*); void setfirstname (struct Employee*, char*); void setlastname (struct Employee*, char*); void settitle (struct Employee*, char*); void setsalary (struct Employee*, int); void printEmployee(struct Employee*); #endif In this file i define the functions and how they work: #include "7.1.h" #include <stdio.h> #include <stdlib.h> #include <string.h> struct Employee* createEmployee(char* first, char* last, char* title, int salary) // Creates a struct Employee object on the heap. { struct Employee* p = (struct Employee*) malloc(sizeof(struct Employee)); if (p != NULL) { strcpy(p->first, first); strcpy(p->last, last); strcpy(p->title, title); p->salary, salary; } return p; } char* getfirstname (struct Employee* p) { if (p != NULL) return p ? p->first : ""; } char* getlastname (struct Employee* p) { if (p != NULL) return p ? p->last : ""; } char* gettitle (struct Employee* p) { if (p != NULL) return p ? p->title : ""; } int getsalary (struct Employee* p) { if (p != NULL) return p ? p->salary : 0; } void setfirstname (struct Employee* p, char* first) { if (p != NULL) strcpy(p->first, first); } void setlastname (struct Employee* p, char* last) { if (p != NULL) strcpy(p->last, last); } void settitle (struct Employee* p, char* title) { if (p != NULL) strcpy(p->title, title); } void setsalary (struct Employee* p, char* salary) { if (p != NULL) p->salary, salary; } void printEmployee(struct Employee* p) { if (p != NULL) { printf("%s, %s, %s, %d", p->first, p->last, p->salary, p->salary ); } } And the last file is used to executed the program/functions: #include "7.1.h" #include <stdio.h> #include <stdlib.h> int main () { char decision; struct Employee emp; struct Employee* emps[3]; for ( int i = 0; i < 1; i ++) { printf("Please type in the emplooyes data.\nFirstname:"); scanf("%s", emp.first); printf("Lastname:"); scanf("%s", emp.last); printf("Title:"); scanf("%s", emp.title); printf("Salary:"); scanf("%d", &emp.salary); emps[i] = createEmployee(emp.first, emp.last, emp.title, emp.salary); } printf("Do you want to print out your information? (Y/N):"); scanf("%c", &decision); if (decision == 'y' || decision == 'Y') { printEmployee(emps[1]); } } I don't know what the problem is. I 'm always getting the following error message after typing in first, last, title and salary for the first time. The error is written in german. It means: Unhandled exception at 0x102de42e (msvcr100d.dll) in 7.1.exe: 0xC0000005: Access violation when writing to 0xCCCCCCCC position. I could fix the first problem with the hints given below. Now when i want to print out the employee data using the function:printEmployee(emps[1]);, I get the same kind of error with access violation.

    Read the article

  • Read from file into pointer to struct

    - by cla barzu
    I need help with pointers in C. I have to read from a file, and fill an array with pointers to struct rcftp_msg . Since now I did the next things: struct rcftp_msg { uint8_t version; uint8_t flags; uint16_t len; uint8_t buffer[512]; }; struct rcftp_msg *windows [10]; pfile = fopen(file,"r"); // Open the file I have to read from the file into the buffer, but I don't know how to do it. I tried the next: for (i = 0; i <10; i++){ leng=fread (**windows[i]->buffer**,sizeof(uint8_t),512,pfile); } I think windows[i]-buffer is bad, cuz that don't work. Sorry for my bad English :(

    Read the article

  • I want to be able to derive from a class internally, but disallow class in other assemblies to derive from the class

    - by Rokke
    Hej I have the following setup: Assembly 1 public abstract class XX<T> : XX where T: YY { } public abstract class XX {} Assembly 2 public class ZZ : YY {} public class ZZFriend : XX<ZZ> {} I use this feature in reflection when in YY: public class YY { public Type FindFriend { return GetType().Assembly.GetTypes().FirstOrDefault( t => t.BaseType != null && t.BaseType.IsGenericType && typeof(XX).IsAssignableFrom(t) && t.BaseType.GetGenericArguments().FirstOrDefault() == GetType()); } } I would like do disallow inheritance of the non generic class XX like: public class ZZFriend: XX {} Alternatively, I need a method like (that can be used in the reflection in YY.FindFrind()): public Type F(Type t) { return GetTypeThatIsGeneric(XX, Type genericTypeParameter); } That can be used in YY as: Typeof(XX<ZZ) == F(typeof(GetType()) Hope that makes sense... Thanks in advance Søren Rokkedal

    Read the article

  • Array as struct database?

    - by user2985179
    I have a struct that reads data from the user: typedef struct { int seconds; } Time; typedef struct { Time time; double distance; } Training; Training input; scanf("%d %lf", input.time.seconds, input.distance); This scanf will be looped and the user can input different data every time, I want to store this data in an array for later use. I THINK I want something like arr[0].seconds and arr[0].distance. I tried to store the entered data in an array but it didn't really work at all... Training data[10]; data[10].seconds = input.time.seconds; data[10].distance = input.distance; The data will wipe when the program closes and that's how I like it to be. So I want it to be stored in an array, no files or databases!

    Read the article

  • any way to simplify this with a form of dynamic class instantiation?

    - by gnychis
    I have several child classes that extend a parent class, forced to have a uniform constructor. I have a queue which keeps a list of these classes, which must extend MergeHeuristic. The code that I currently have looks like the following: Class<? extends MergeHeuristic> heuristicRequest = _heuristicQueue.pop(); MergeHeuristic heuristic = null; if(heuristicRequest == AdjacentMACs.class) heuristic = new AdjacentMACs(_parent); if(heuristicRequest == SimilarInterfaceNames.class) heuristic = new SimilarInterfaceNames(_parent); if(heuristicRequest == SameMAC.class) heuristic = new SameMAC(_parent); Is there any way to simplify that to dynamically instantiate the class, something along the lines of: heuristic = new heuristicRequest.somethingSpecial(); That would flatten that block of if statements.

    Read the article

  • A Reusable Builder Class for Ruby Testing

    - by Liam McLennan
    My last post was about a class for building test data objects in C#. This post describes the same tool, but implemented in Ruby. The C# version was written first but I originally came up with the solution in my head using Ruby, and then I translated it to C#. The Ruby version was easier to write and is easier to use thanks to Ruby’s dynamic nature making generics unnecessary.  Here are my example domain classes: class Person attr_accessor :name, :age def initialize(name, age) @name = name @age = age end end class Property attr_accessor :street, :manager def initialize(street, manager) @street = street @manager = manager end end and the test class showing what the builder does: class Test_Builder < Test::Unit::TestCase def setup @build = Builder.new @build.configure({ Property => lambda { Property.new '127 Creek St', @build.a(Person) }, Person => lambda { Person.new 'Liam', 26 } }) end def test_create assert_not_nil @build end def test_can_get_a_person @person = @build.a(Person) assert_not_nil @person assert_equal 'Liam', @person.name assert_equal 26, @person.age end def test_can_get_a_modified_person @person = @build.a Person do |person| person.age = 999 end assert_not_nil @person assert_equal 'Liam', @person.name assert_equal 999, @person.age end def test_can_get_a_different_type_that_depends_on_a_type_that_has_not_been_configured_yet @my_place = @build.a(Property) assert_not_nil @my_place assert_equal '127 Creek St', @my_place.street assert_equal @build.a(Person).name, @my_place.manager.name end end Finally, the implementation of Builder: class Builder # defaults is a hash of Class => creation lambda def configure defaults @defaults = defaults end def a(klass) temp = @defaults[klass].call() yield temp if block_given? temp end end

    Read the article

  • VS 2010 IDE Features in a nutshell

    - by Rajesh Pillai
    Going through a VS 2010 IDE Features.  We will explore each feature in subsequent posts.  The post are documented as being reviewed by me.   Breakpoint Labeling Breakpoint Searching Breakpoint Import/Export Dynamic Data Tooling WPF Tree Visualizer Call Hierarchy Improved WPF Tooling Historical Debugging Mini-Dump Debugging Quick Search Better Multi-Monitor Support Highlight References Parallel Stacks Window Parallel Tasks Window Document Map Margin Generate from Usage Concurrency Profiler Inline Call Tree Extensible Test Runner MVC Tooling Web Deploy JQuery IntelliSense SharePoint Tooling HTML Snippets Web.config Transformation ClickOnce Enhancements for MS Office     VS is an editor as well as a platform for development and this is only more true with VS 2010.  As an editor there is improved forcus on writing code, understanding code, navigating and publishing code.   VS Shell has been completely rewritten using WPF extending huge benefits.  The start page has been rewritten using XAML, so it is easy to customize.   Support new support for Silverlight, MFC, F# , Azure and extended support for Office 2010, Sharepoint.   Has a good Extension Manager as well.   Enjoy Coding !!!

    Read the article

  • Strategies for invoking subclass methods on generic objects

    - by Brad Patton
    I've run into this issue in a number of places and have solved it a bunch of different ways but looking for other solutions or opinions on how to address. The scenario is when you have a collection of objects all based off of the same superclass but you want to perform certain actions based only on instances of some of the subclasses. One contrived example of this might be an HTML document made up of elements. You could have a superclass named HTMLELement and subclasses of Headings, Paragraphs, Images, Comments, etc. To invoke a common action across all of the objects you declare a virtual method in the superclass and specific implementations in all of the subclasses. So to render the document you could loop all of the different objects in the document and call a common Render() method on each instance. It's the case where again using the same generic objects in the collection I want to perform different actions for instances of specific subclass (or set of subclasses). For example (an remember this is just an example) when iterating over the collection, elements with external links need to be downloaded (e.g. JS, CSS, images) and some might require additional parsing (JS, CSS). What's the best way to handle those special cases. Some of the strategies I've used or seen used include: Virtual methods in the base class. So in the base class you have a virtual LoadExternalContent() method that does nothing and then override it in the specific subclasses that need to implement it. The benefit being that in the calling code there is no object testing you send the same message to each object and let most of them ignore it. Two downsides that I can think of. First it can make the base class very cluttered with methods that have nothing to do with most of the hierarchy. Second it assumes all of the work can be done in the called method and doesn't handle the case where there might be additional context specific actions in the calling code (i.e. you want to do something in the UI and not the model). Have methods on the class to uniquely identify the objects. This could include methods like ClassName() which return a string with the class name or other return values like enums or booleans (IsImage()). The benefit is that the calling code can use if or switch statements to filter objects to perform class specific actions. The downside is that for every new class you need to implement these methods and can look cluttered. Also performance could be less than some of the other options. Use language features to identify objects. This includes reflection and language operators to identify the objects. For example in C# there is the is operator that returns true if the instance matches the specified class. The benefit is no additional code to implement in your object hierarchy. The only downside seems to be the lack of using something like a switch statement and the fact that your calling code is a little more cluttered. Are there other strategies I am missing? Thoughts on best approaches?

    Read the article

  • Python class representation under the hood

    - by decentralised
    OK, here is a simple Python class: class AddSomething(object): __metaclass__ = MyMetaClass x = 10 def __init__(self, a): self.a = a def add(self, a, b): return a + b We have specified a metaclass, and that means we could write something like this: class MyMetaClass(type): def __init__(cls, name, bases, cdict): # do something with the class Now, the cdict holds a representation of AddSomething: AddSomething = type('AddSomething', (object,), {'x' : 10, '__init__': __init__, 'add': add}) So my question is simple, are all Python classes represented in this second format internally? If not, how are they represented? EDIT - Python 2.7

    Read the article

  • Do first-class methods exist?

    - by gdhoward
    Okay, I know first-class functions are cool, closures even better, etc. But is there any language with first-class methods? In my mind, I see a first-class method as an "object" that has both a function pointer and a pointer to a specific instance of the class/object, but the implementation doesn't matter. I just want to know if there is any language that uses them. And as a bonus, how were they implemented?

    Read the article

  • How to decide to which class does a method belong

    - by Eleeist
    I have TopicBusiness.class and PostBusiness.class. I have no problem with deciding into which class methods such as addPostToDatabase() or getAllPostsFromDatabase() should go. But what about getAllPostsFromTopic(TopicEntity topic) or getNumberOfPostsInTopic(TopicEntity topic)? Should the parameter be the deciding factor? So when the method takes TopicEntity as parameter it should belong to TopicBusiness.class? I am quite puzzled by this.

    Read the article

  • java class creation dynamically and make it accessible across the network different jvms i.e. serial

    - by inj.rav
    Hi. I have a requirement of creating java classes dynamically and make it accessible different jvms across the network. I tried to use reflection and javassist tool,but nothing worked. Let me explain the scenario we are using Coherence distributed cache. It has a power of doing aggregation/filtering in parallel across the cluster. For example if a class has [dynamic class] has amount variable and getAmount/setAmount methods. Then if we execute COHERENCE queries, it will start process in parallel across the cluster. I tried to create classes at run time by using javassist and reflection. I am able to access it from single JVM, but when I tried to access the same class from other jvm [through coherence cluster]. I am getting exception of class not found [as remote jvm is not having idea of this class].I can over come this by creating same class dynamically on remote jvm also and access the methods. But coherence in built methods/functions are not able to find the class. could some one help me on this matter

    Read the article

  • Database class is not correctly connecting to my database.

    - by blerh
    I'm just venturing into the world of OOP so forgive me if this is a n00bish question. This is what I have on index.php: $dbObj = new Database(); $rsObj = new RS($dbObj); This is the Database class: class Database { private $dbHost; private $dbUser; private $dbPasswd; private $dbName; private $sqlCount; function __construct() { $this->dbHost = 'localhost'; $this->dbUser = 'root'; $this->dbPasswd = ''; $this->dbName = 'whatever'; $this->sqlCount = 0; } function connect() { $this->link = mysql_connect($this->db_host, $this->db_user, $this->db_passwd); if(!$this->link) $this->error(mysql_error()); $this->selection = mysql_select_db($this->db_name, $this->link); if(!$this->selection) $this->error(mysql_error()); } } I've shortened it to just the connect() method to simplify things. This is the RS class: class RS { private $username; private $password; function __construct($dbObj) { // We need to get an account from the db $dbObj->connect(); } } As you can probably see, I need to access and use the database class in my RS class. But I get this error when I load the page: Warning: mysql_connect() [function.mysql-connect]: Access denied for user 'ODBC'@'localhost' (using password: NO) in C:\xampp\htdocs\includes\database.class.php on line 22 The thing is I have NO idea where it got the idea that it needs to use ODBC as a user... I've read up on doing this stuff and from what I can gather I am doing it correctly. Could anyone lend me a hand? Thank you.

    Read the article

< Previous Page | 45 46 47 48 49 50 51 52 53 54 55 56  | Next Page >