Search Results

Search found 23792 results on 952 pages for 'void pointers'.

Page 153/952 | < Previous Page | 149 150 151 152 153 154 155 156 157 158 159 160  | Next Page >

  • C++ performance, optimizing compiler, empty function in .cpp

    - by Dodo
    I've a very basic class, name it Basic, used in nearly all other files in a bigger project. In some cases, there needs to be debug output, but in release mode, this should not be enabled and be a NOOP. Currently there is a define in the header, which switches a makro on or off, depending on the setting. So this is definetely a NOOP, when switched off. I'm wondering, if I have the following code, if a compiler (MSVS / gcc) is able to optimize out the function call, so that it is again a NOOP. (By doing that, the switch could be in the .cpp and switching will be much faster, compile/link time wise). --Header-- void printDebug(const Basic* p); class Basic { Basic() { simpleSetupCode; // this should be a NOOP in release, // but constructor could be inlined printDebug(this); } }; --Source-- // PRINT_DEBUG defined somewhere else or here #if PRINT_DEBUG void printDebug(const Basic* p) { // Lengthy debug print } #else void printDebug(const Basic* p) {} #endif

    Read the article

  • behavior of memset

    - by Vinicius Horta
    Does this function has the same behavior that 'memset'? (Oops! Your question couldn't be submitted because: Your post does not have much context to explain the code sections; please explain your scenario more clearly. ) inline void SetZeroArray( void *vArray[], unsigned int uArraySize ) { for(unsigned i=0; i<=uArraySize; i++ ) vArray[i] = NULL; } int main( int argc, char *argv[] ) { unsigned int uLevels[500]; SetZeroArray( (void**)uLevels, 500 ); unsigned int ulRLevels[500]; memset( &ulRLevels, 0, sizeof( ulRLevels ) ); system("pause>nul"); return EXIT_SUCCESS; }

    Read the article

  • UIWebView appears null when calling fro a method

    - by Alexidze
    I have a major problem when trying to access a UIWebView that was created during ViewDidLoad, the UIWebView appears null here is how i declare the property @property (nonatomic, retain) UIWebView *detailsView; the implementation @implementation iPadMainViewController @synthesize detailsView; - (void)viewDidLoad { [super viewDidLoad]; detailsView = [[UIWebView alloc] initWithFrame:CGRectMake(500, 0, 512, 768)]; [self.view addSubView:detailsView]; } When accessing from - (void)loadDetailedContent:(NSString *)s { NSLog(@"%@", detailsView); } I get NULL, is it a normal behavior or am i doing something wrong? here is the touchesBegan that is being called, from the views subclass that is being touched, -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { iPadMainViewController *mycontroller = [[iPadMainViewController alloc] init]; self.delegate = mycontroller; [self.delegate loadDetailedContent:NewsId]; }

    Read the article

  • Java Inheritance Concept Understanding

    - by Nirmal
    Hello All.... I am just refreshing the oops features of the java. So, I have a little confusion regarding inheritance concept. For that I have a following sample code : class Super{ int index = 5; public void printVal(){ System.out.println("Super"); } } class Sub extends Super{ int index = 2; public void printVal(){ System.out.println("Sub"); } } public class Runner { public static void main(String args[]){ Super sup = new Sub(); System.out.println(sup.index+","); sup.printVal(); } } Now above code is giving me output as : 5,Sub. Here, we are overriding printVal() method, so that is understandable that it is accessing child class method only. But I could not understand why it's accessing the value of x from Super class... Thanks in advance....

    Read the article

  • Accessing a function of an instance which is in an arraylist

    - by fadeir
    I'm tring to access a function of an instance which is in an arraylist. Is there any way to do that without using the class name of the instance? import java.util.ArrayList; import java.util.List; class apple{ int price; public void myFunction(int iPrice) { price=iPrice; } } class orange{ int price; public void myFunction(int iPrice) { price=iPrice; } } public class main { public static void main(String[] args) { List list= new ArrayList(); //create 3 apple object to list list.add( new apple() ); list.add( new apple() ); list.add( new orange() ); list.get(0).myFunction(1); /* Error: The method myFunction(int) is undefined for the type Object*/ } } I know that;((apple) list.get(0)).myFunction(1); is a way but I'dont want to use any class name while calling the function.

    Read the article

  • ASP.NET null reference exception

    - by nanek
    Please help me to figure out what is wrong with this code: I have ASP.NET page with one button visible. When user clicks it - it instances MyClass (its implementation is in AppCode directory) and turns invisible (button2 becomes visible). When I click button2 it raises "Object reference not set to an instance of an object" Exception. What seems to be the problem? { public MyClass noviTest; protected void Page_Load(object sender, EventArgs e) { } protected void Button1_Click(object sender, EventArgs e) { noviTest = new MyClass(TextBox1.Text); Button1.Visible = false; Button2.Visible = true; } protected void Button2_Click(object sender, EventArgs e) { Label1.Text=noviTest.getID; //this is the critical line } } Thank You in advance, Regards

    Read the article

  • About using assembly with c

    - by kristus
    Hi. I've sort of just finished a mandatory task at school, and I'm about to deliver it. But then I came across something that was unfamiliar, header files. :( What I've got: test-program.c task_header.h function1.s function2.s function3.s function4.s test-program.c: #include <stdio.h> #include <stdlib.h> #include <string.h> #include "task_header.h" . .. ... task_header.h: extern void function1(...); extern void function2(...); extern int function3(...); extern void function4(...); And then I use the command: gcc -m32 -o runtest test-program.c function1.s function2.s function3.s function4.s Is this a proper way to do it, or is it possible to modify it? So I can type: gcc -m32 -o runtest test-program.c ?

    Read the article

  • Why would you precede the main() function in C with a data type?

    - by Milktrader
    Many are familiar with the hello world program in C #include <stdio.h> main () { printf ("hello world"); return 0; } Why do some precede the main () function with int as in: int main() Also, I've seen the word 'void' entered inside the () as in: int main(void) It seems like extra typing for nothing, but maybe it's a best practice that pays dividends in other situations? Also, why precede main() with an int if you're returning a character string? If anything, one would expect: char main(void) I'm also foggy about why we return 0 at the end of the function.

    Read the article

  • C#: Searching through arrays

    - by Jonathan Oberhaus
    I have a dvd app that stores dvds and blu-rays, I want to search the arrays by director. Below is the code for the inventory class I have seen many different ways to do this. There seems to be some debate as the best/most efficient way to accomplish this, any suggestions? Blockquote namespace MovieInventoryApplication { class Inventory { public Bluray[] BlurayMovies; public DVD[] DVDMovies; private int blurayCount; private int dvdCount; public Inventory() { BlurayMovies = new Bluray[5]; DVDMovies = new DVD[5]; blurayCount = 0; dvdCount = 0; } public void AddBluray() { String strTitle; int intReleaseYear; int intRunningTimeMinutes; String strDirector; int intPrice; int intRegionCode; try { Console.Write("Enter a title: "); strTitle = Console.ReadLine(); Console.Write("Enter a release year: "); intReleaseYear = Convert.ToInt32(Console.ReadLine()); Console.Write("Enter the running time in minutes: "); intRunningTimeMinutes = Convert.ToInt32(Console.ReadLine()); Console.Write("Enter the directors name: "); strDirector = Console.ReadLine(); Console.Write("Enter a rental price: "); intPrice = Convert.ToInt32(Console.ReadLine()); BlurayMovies[blurayCount] = new Bluray(strTitle, intReleaseYear, intRunningTimeMinutes, strDirector, intPrice); blurayCount++; Console.Write("Enter the DVD region code: "); intRegionCode = Convert.ToInt32(Console.ReadLine()); DVDMovies[dvdCount] = new DVD(strTitle, intReleaseYear, intRunningTimeMinutes, strDirector, intPrice, intRegionCode); dvdCount++; } catch (FormatException FormatException) { Console.WriteLine(FormatException.Message); Console.WriteLine("Please enter a number in this field."); } } public void AddDVD() { String strTitle; int intReleaseYear; int intRunningTimeMinutes; String strDirector; int intPrice; int intRegionCode; try { Console.Write("Enter a title: "); strTitle = Console.ReadLine(); Console.Write("Enter a release year: "); intReleaseYear = Convert.ToInt32(Console.ReadLine()); Console.Write("Enter the running time in minutes: "); intRunningTimeMinutes = Convert.ToInt32(Console.ReadLine()); Console.Write("Enter the directors name: "); strDirector = Console.ReadLine(); Console.Write("Enter a rental price: "); intPrice = Convert.ToInt32(Console.ReadLine()); Console.Write("Enter the region code: "); intRegionCode = Convert.ToInt32(Console.ReadLine()); DVDMovies[dvdCount] = new DVD(strTitle, intReleaseYear, intRunningTimeMinutes, strDirector, intPrice, intRegionCode); dvdCount++; } catch (FormatException FormatException) { Console.WriteLine(FormatException.Message); Console.WriteLine("Please enter a number in this field."); } } public void ListAllBluray() { int position = 0; while (BlurayMovies[position] != null) { Console.WriteLine(position + " " + BlurayMovies[position].strTitle); position++; } } public void ListAllDVD() { int position = 0; while (DVDMovies[position] != null) { //position + 1 + " " + Console.WriteLine(position + " " + DVDMovies[position].strTitle); position++; } } public void BlurayInfo(int position) { Console.WriteLine("Title: {0}", DVDMovies[position].strTitle); Console.WriteLine("Release Year: {0}", DVDMovies[position].intReleaseYear); Console.WriteLine("Running Time (Minutes): {0}", DVDMovies[position].intRunningTimeMinutes); Console.WriteLine("Director: {0}", DVDMovies[position].strDirector); Console.WriteLine("Price: {0}", DVDMovies[position].intPrice); } public void DVDInfo(int position) { Console.WriteLine("Title: {0}", DVDMovies[position].strTitle); Console.WriteLine("Release Year: {0}", DVDMovies[position].intReleaseYear); Console.WriteLine("Running Time (Minutes): {0}", DVDMovies[position].intRunningTimeMinutes); Console.WriteLine("Director: {0}", DVDMovies[position].strDirector); Console.WriteLine("Price: {0}", DVDMovies[position].intPrice); Console.WriteLine("Region Code: {0}", DVDMovies[position].intRegionCode); } } }

    Read the article

  • doubt in Exceptions

    - by Ajay Singh
    class MyException extends Exception { MyException() {} MyException(String msg) { super(msg);} } public class NewException { static void f() throws MyException { System.out.println("throwing exception from f()"); throw new ClassCastException(); } static void g() throws MyException { System.out.println("throwing exception from g()"); throw new MyException("parametrized "); } public static void main(String ...strings ) { try { f(); } catch(MyException e) { e.printStackTrace(System.out); } try { g(); } catch(MyException e) { e.printStackTrace(System.out); } } } In the function f() iam specifying that "MyException " exception will be thrown and actually iam throwing some other exception which has no relation with MyException but still the compiler does not report any complain.Why is it so??

    Read the article

  • C - Call a function

    - by Pedro
    Hello. I want to get a value from a function in other function i think i have to call a function in other function, then call it on main, but how? void funcA(PEOPLE people[], int *total){ FILE *fp; char line[100]; fp=fopen("example.txt","r"); if(fp==NULL){ exit(1); } else{ fgets(line, 100, fp);//get a number from the txt total=atoi(linha);//convert to int } } void funcB(PEOPLE people[], int *total){ int i; for(i=0;i<total;i++){ printf("%s\n",people[i].name); } funcA(people,&total); } void main(){ PERSON person[100]; int *total; funcB(people,&total); } What i'm doing wrong?

    Read the article

  • XAML-based applications - Event Naming Conventions for C#

    - by user118190
    For event handling, I am starting to see many coders doing this: XButton.Click += OnXButtonClicked() ... void OnXButtonClicked() { ... } Where did this On_ convention come from? It just doesn't feel right in terms of methods. I am starting to see this as well and am wondering what others thought: XButton.Click += HandleXButtonClick() ... void HandleXButtonClick() { ... } When using intellisense, Visual Studio handles these like so: XButton.Click += XButton_Click; ... void XButton_Click(object sender, RoutedEventArgs e) { ... } I am seeking some advice on these naming conventions and would greatly appreciate some advice.

    Read the article

  • Why this function overloading is not working?

    - by Jack
    class CConfFile { public: CConfFile(const std::string &FileName); ~CConfFile(); ... std::string GetString(const std::string &Section, const std::string &Key); void GetString(const std::string &Section, const std::string &Key, char *Buffer, unsigned int BufferSize); ... } string CConfFile::GetString(const string &Section, const string &Key) { return GetKeyValue(Section, Key); } void GetString(const string &Section, const string &Key, char *Buffer, unsigned int BufferSize) { string Str = GetString(Section, Key); // *** ERROR *** strncpy(Buffer, Str.c_str(), Str.size()); } Why do I get an error too few arguments to function ‘void GetString(const std::string&, const std::string&, char*, unsigned int)' at the second function ? Thanks

    Read the article

  • Java Thread Message Passing

    - by pkulak
    I'm writing an Android app. I have a main method, which creates and runs a new Thread using an anonymous inner Runnable class. The run() method, when it's done, calls a method on it's parent class (in the main thread) that calls notifyDataSetChanged() so that the main thread can redraw the new data. This is causing all kinds of trouble (ViewRoot$CalledFromWrongThreadException). The thing is, this method being called from the worker thread is on the class that's created in the UI thread. Shouldn't that be running on the UI thread? Or am I missing something? Here's some code about what I'm talking about: public class Mealfire extends Activity { @Override public void onCreate(Bundle icicle) { (new Thread() { public void run() { // Do a bunch of slow network stuff. update(); } }).start(); } private void update() { myAdapter.notifyDatasetChanged(); } }

    Read the article

  • C++ Basic Class Layout

    - by Spencer
    Learning C++ and see the class laid out like this: class CRectangle { int x, y; public: void set_values (int,int); int area () {return (x*y);} }; void CRectangle::set_values (int a, int b) { x = a; y = b; } I know Java and methods(functions) in Java are written within the class. The class looks like a Java interface. I know I can write the class like this: class CRectangle { int x, y; public: void set_values (int a, int b) { x = a; y = b; }; int area () {return (x*y);} }; But is there a difference or standard?

    Read the article

  • Solving C++ 'target of assignment not really an lvalue' errors

    - by Jason
    Given this code: void FrMemCopy(void *to, const void *from, size_t sz) { size_t sz8 = sz >> 3; size_t sz1 = sz - (sz8 << 3); while (sz8-- != 0) { *((double *)to)++ = *((double *)from)++; } while (sz1-- != 0) { *((char *)to)++ = *((char *)from)++; } } I am receiving target of assignment not really an lvalue warnings on the 2 lines inside the while loops. Can anyone break down those lines? a cast then an increment? What is a simplier way to write that? What does the error mean?

    Read the article

  • How to Choose a Link Building Service That Gives Results

    Are you skeptical about hiring a link building service? Are you worried that you just might fall into the hands of the dreaded scammers who promise "heaven" (top search engine rankings) and give "hell" (de-indexing from the search engines or penalties)? Would you like to know what you can do to weed out the fakes and hire a truly reputable SEO service? Here are a few pointers in that direction.

    Read the article

  • Debug.writeline locks

    - by Carra
    My program frequently stops with a deadlock. When I do a break-all and look at the threads I see that three threads are stuck in our logging function: public class Logging { public static void WriteClientLog(LogLevel logLevel, string message) { #if DEBUG System.Diagnostics.Debug.WriteLine(String.Format("{0} {1}", DateTime.Now.ToString("HH:mm:ss"), message)); //LOCK #endif //...Log4net logging } } If I let the program continue the threads are still stuck on that line. I can't see where this can lock. The debug class, string class & datetime class seem to be thread safe. The error goes away when I remove the "#if DEBUG System... #endif" code but I'm curious why this behavior happens. Thread one: public void CleanCache() { Logging.WriteClientLog(LogLevel.Debug, "Start clean cache.");//Stuck } Thread two: private void AliveThread() { Logging.WriteClientLog(LogLevel.Debug, "Check connection");//Stuck }

    Read the article

  • How can I implement a matchmaker?

    - by csiz
    I'm making a multiplayer game, where players are separated in to rooms that would ideally have about 20 players. So I need a few pointers on an algorithm to distribute the players in to these rooms. A few more constraints: When a players gets in to a room, he should stay there until he decides to exit (the room itself changes levels) There may be more room servers, every server should create more rooms until near full capacity There's a central server that manages all the room servers, and directs the players towards their room

    Read the article

  • Please see following code and answer

    - by user323422
    template <class T> class _cExplicitInstation { public: void show1(T c) { double d =10.02 ; std::cout<<c; } void show2(T d) { std::cout<<d; } }; template _cExplicitInstation<char>; template void _cExplicitInstation<int>::show1(int c); int main() { _cExplicitInstation<char> abc; _cExplicitInstation<int>().show2(10);// it should show error as i have // explicitly declare for show1() function but its working // can u tell why? }

    Read the article

  • Is there some way to assume @Nullable as default? (using FindBugs or any other free tool).

    - by alex2k8
    Consider such code public void m1(String text) { if(text == null) text = "<empty>"; System.out.println(text.toLowerCase()); } And this is a buggy version: public void m1(String text) { System.out.println(text.toLowerCase()); } If null value passed, the NullPointerException may be thrown. I would like the static-analysis tool (e.g. FindBugs) to report this issue. Unsuccessfully the FindBugs (at least by default) requires me to specify @Nullable annotation explicitly. public void m1(@Nullable String text) { System.out.println(text.toLowerCase()); // FindBugs: text must be nonnull but is marked as nullable } The problem is that if I forget to annotate it, the bug will be missed!!! How can I make the FindBugs (or any other free tool) to assume @Nullable by default?

    Read the article

  • Global variable in a recursive function how to keep it at zero?

    - by Grammin
    So if I have a recursive function with a global variable var_: int var_; void foo() { if(var_ == 3) return; else var_++; foo(); } and then I have a function that calls foo() so: void bar() { foo(); return; } what is the best way to set var_ =0 everytime foo is called thats not from within itself. I know I could just do: void bar() { var_ =0; foo(); return; } but I'm using the recursive function a lot and I don't want to call foo and forget to set var_=0 at a later date. Does anyone have any suggestions on how to solve this? Thanks, Josh

    Read the article

  • Event handling C# / Registering a callback

    - by Jeff Dahmer
    Events can only return void and recieve object sender/eventargs right? If so then craptastic.... how can I pass a function pointer to another obj, like: public bool ACallBackFunc(int n) { return n > 0; } public void RegisterCallback(Something s) { s.GiveCallBack(this.ACallBackFunc); } Something::GiveCallBack(Action? funcPtr) I tried using Action, but I need it to return some value and Actions can only return void. Also, we do not know what kind of a callback we will be recieving; it could return anything and have any params! Reflection will have to be used somehow I reckon.

    Read the article

  • Overriding vs Virtual

    - by anonymous
    What is the purpose of using the reserved word virtual in front of functions? If I want a child class to override a parent function, I just declare the same function such as "void draw(){}". class Parent{ public: void say(){ std::cout << "1"; }}; class Child : public Parent{public:void say(){ std::cout << "2"; } }; int main() { Child* a = new Child(); a->say(); return 0; } The output is 2. So again, why would the reserved word "virtual" be necessary in the header of say() ? Thanks a bunch.

    Read the article

  • What does this recursive function do?

    - by null
    What does this function do? And how do you evaluate it? How to trace it? How to understand recursive method? I just can't understand the recursion, and the exam date is coming soon, and I know in order to understand recursion, I must first understand recursion. But I just can't write a slightly complex recursive method, can anyone help me out using the simplest English words. public class BalancedStrings { public static void printBalanced(String prefix, int a, int b) { if (a > 0) printBalanced(prefix + "a", a - 1, b); if (b > 0) printBalanced(prefix + "b", a, b - 1); if (a == 0 && b == 0) System.out.println(prefix); } public static void printBalanced(int n) { if (n % 2 == 0) { printBalanced("", n / 2, n / 2); } } public static void main(String[] args) { printBalanced(4); } }

    Read the article

< Previous Page | 149 150 151 152 153 154 155 156 157 158 159 160  | Next Page >