getting an invalid null pointer error message after a successful build. This program is supposed to ask for firstName, lastName, age and maJor and keep doing so until the age that is input is 0 and then the program closes. Here is what I have.
#include <iostream>
#include <string>
using namespace std;
[Code]....
I have a class like this:
#include <string>
using namespace std;
//-----------------------------------------------
class Prenumeratorius {
private:
string pavarde;
string adresas;
string leidinioKodas;
[code]....
bunch of variables, constructor, setter and getter.And I have this class:
#include <vector>
class Leidinys {
private:
string kodas;
string pavadinimas;
double vienetoKaina;
[code]....
in to my "Leidinys.h" header file, I get a build error, I tried to remove same includes in both files, that didn't worked.
After looking online for a string replace function in C and finding so many examples that go through the entire string twice. First round to find how number of occurances of substitute in string, using that to malloc for a new string to include additional space for replace, then going through the search string again to get all but what's to be substituted out. I feel it's kind of silly to go through the string twice. Therefore, I'm trying to implement my own string replace, that only searches through the string for what's to be substituted, once.
Here is my code:
Code:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
char *strreplace(char * string, char * sub, char * replace);
}
[code]....
Here is the same code, but with execution + some syntax highlighting: Ideone.com | Online C Compiler & Debugging Tool..It works great, until it gets to grabbing whatever remains in the search string after the last found sub. The realloc throws a runtime error:
Code:
*** glibc detected *** ./a.out: realloc(): invalid next size: 0x00011008 ***
Aborted From my understanding, this is from me going outside of the bounds of the heap and using memory I haven't allocated, or using a free'd pointer. I'm not seeing where either of these are happening in my code, and was wondering what the best way to go about figuring out where the error exactly occurs.
The exercise consists on 3 procedures. We get the information from a .txt like these:
01/03/2011 A
02/03/2011 F
03/03/2011 C
04/03/2011 T
(...)
Simulating a Videoclub database where the letters stand for the type of movie (A=Action, T=Terror, C=Comedy, ...) and the dates they were rented.
a) How many movies from one specific genre have been rented more than 'n' times? The genre and the value 'n' must be entered by the user.
b) How many movies and which genres belong to a certain date? The date must be entered by the user.
c) Print a list that shows the number of times a movie from each genre has been rented.
So far this is what I've got:
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 100
typedef struct {
int dia,mes, any;
char genere;
[Code] ....
But right now, my main problem is that I can't even debug because i get an error in line 97 --> while (llista[i][j] != EOF) <-- saying "invalid operands to binary != (have 'lloguer' and 'int').
I've tried to cast (int) before "llista[i][j]" but it says that I'm already supposed to get an integer from that.
In my raytracer-project I have the following function:
bool hitObjects(Ray &ray, std::vector<Object *> &objects, Vector3& normal, Material *mat) {
double tmin = K_HUGE_VALUE;
double t;
[Code]....
When I try to run this, I only get the message "Material pointer is null". So, somehow the pointer is null after the hitObjects-function is called, even though it isn't inside that function.
So I'm writing a small program for class, and for some reason I keep getting an error when trying to initialize head to NULL. Even threw in the namespace just to see, nothin'.
#ifndef NUMBERLIST_H
#define NUMBERLIST_H
using namespace std;
[Code].....
There's my header file. Not sure what I'm doing wrong with the constructor.
EDIT: Got it to work with nullptr, but still curious why that isn't working
I keep getting an error "Invalid use of void expression" on line 12.
Code:
#include<stdio.h>
#include<stdlib.h>
void initialiaze_array( int size );
void print_array( int size );
void replace( int num, int i );
[Code] ....
In jumping into C++ it says something like this: It's not necessary but when you delete a pointer it's a good idea to reset it as a null pointer. That if your code try's to dereference the pointer after being freed, your program will crash. This happens to a lot of experienced programmers.
This could corrupt users data. delete p_int;
p_int = NULL;
1. If you can deference a pointer after the memory is freed, why can't you just delete the pointer?
2. If you can do 1, how do you delete the pointer using code?
3. Every thing I've read says that free memory is handed out in a sequenced order. I don't believe that is true at all. I may be wrong. Why can't you put the data in any number of places if it will fit. Isn't the compiler smart enough to know where bytes (bits)and pieces are stored?
4. If you storing anything in free memory must use a pointer to it?
5. Can a pointer or something similar be used with stack memory?
in the below program for both class pointers pointing to null. Class contains normal function executing but class contains virtual function getting segmentation fault.
#include <cstdio>
using namespace std;
class A
{
[Code].....
Here when NonlinearSolver called the constructor,
m_gradient() constructor is called to construct m_gradient, which in turns sets a variable called m_S to NULL(0), then in the assignment operator, because the m_S is NULL, Visual Studio throws an exception saying that destination pointer is null, but it's not fatal. I don't like that to happen because I have to press ignore many many times when the program is debugged, how can I fix this bug (not mine) to avoid the null destination pointer exception?
As an intermediate layer, the function calls boost unbounded array operator = which in turns calls std::copy which results in this error
Code:
NonlinearSolver(solver_type const & solver)
: m_gradient()
, m_function()
, m_projection() {
*this = solver;
[Code] .....
I am using visual studio 2012 on windows 7. but, when I have compiled my programs and run them on an older pc to test out its functions, I receive an error saying that the program is not a "valid win32 application." I have even tested this with a very simple hello world console application, but the problem still remains. Where is the error coming from? is the application corrupted during transport? (upload to internet) or are programs compiled on win 7 incompatible with win xp
View 6 Replies View RelatedThe compiler keeps on telling me that invalid conversion from wxBitmap* to wxString on the line with the AddTool function, whiles I do not even try to do such an ambiguous typecast.
wxWidgets 2.9.4
MinGW
gdb
Code:
#include "mainwnd.h"
//namespaces
//other definitions and declarations
CMAINWND::CMAINWND(const wxString& szTitle):wxFrame(NULL,wxID_ANY,szTitle) {
wxImage::AddHandler(new wxBMPHandler);
[Code] .....
I making a simple single number scrambler/encryptor and as I tried to build the console application the following error
occurred:
error: invalid operands of types 'void' and 'int' to binary 'operator%'
The source code is bellow.
#include <iostream>
#include <math.h>
#include <cstdlib>
using namespace std;
int main() {
int nTimer;
int nInput;
[Code]......
I am running code::blocks as my IDE on Ubuntu.
lets say I have a pointer p_unit of type c_unit* (c_unit is an a.b.c.)
I have a function that returns a pointer to a new c_unit object:
c_unit * man_add_unit() {
c_unit * local_p_unit;
unsigned short int local_run_code;
print_man_add_menu();
local_run_code = get_a_run_code(); // this bit just gets user input
switch (local_run_code)
[code]....
I assign that to p_unit, then add it to a vector v_units:
p_unit = man_add_unit();
v_units.push_back(p_unit);
cout << "New unit added.
";
The whole program runs on a loop, and another thing the user can do is to print out data on c_unit objects pointed to by v_units. The problem is, in that function up there ^ I give the user the option to go back to main menu without creating a unit.
Since "local_p_unit" is declared but not assigned an initial value, I'm guessing the function would return a "null" pointer (which is what's hanging me up). If I just let this run with the above code, and go to print out the unit data, the program crashes.
I tried to make an if thing with p_unit == 0 but this always returns false and doesn't catch the "bad" unit that will subsequently cause a crash.
Btw, I have considered assigning a reference to a generic c_unit object to that there local_p_unit so it won't return null, then remove pointers to that object from v_units at the end of the loop.. But I know there's got to be a better way.
struct mystruct{
int n;
};
class mscope{
public:
std::vector<mystruct> mv;
[Code] .....
So I have a vector of structs and I want to traverse it, find a struct that matches a constraint and obtain a pointer to that struct. I made a function for this purpose which takes a number and an empty pointer that will store the reference. However, after function returns the pointer becomes null. What could be causing this?
Code:
class Base {
public:
int base;
Base(int init=0):base(init){}
virtual ~Base(){}
[Code] .....
Invalid initialization of non-const reference of type 'Base&' from an rvalue of type 'Derived'
What does it mean, and why can't I return the Derived class by value (I'm trying to create an exact copy of Derived).
So the thing is I have 2 forms, form 1 is displayed first, and form2 would be open when click the next button on form1.
So i was success in moving to the next form, and even getting back to the previous, and then next again, but on the second time I try to go back from form2 to form 1, this error show up.
The error:
Form that is already displayed modally cannot be displayed as a modal dialog box. Close the form before calling showDialog.
This is my sample code:
Form1 next button
private void button2_Click_1(object sender, EventArgs e)
{
this.Hide();
[Code].....
I am trying to use the Singleton design patterno on Linux, but it is not working:
in the .h I have:
Code:
public:
static ErrorH& Instance();
private:
ErrorH() {};
In the .cpp I have:
Code:
ErrorH& ErrorH::Instance() {
static ErrorH& self = ErrorH();
return self;
}
The errors I get are:
Code:
g++ --g -c ErrorH.cpp -o ErrorH.o
ErrorH.cpp: In static member function "static ErrorH& ErrorH::Instance()":
ErrorH.cpp:9: error: invalid initialization of non-const reference of type "ErrorH&" from a temporary of type "ErrorH"
make: *** [ErrorH.o] Error 1
This code works on Windows, how can I get it to work on Linux?
i want to modify value of whole array by passing it to a function and make each value of array multiplied by 3 ,return the value to main and print it using pointer.
error : invalid Lvalue is the error
Code:
#include<stdio.h>
main()
{
int i,arr[10];
for (i=0;i<=9;i++)
{
printf("Enter value of arr[%d] : ",i);
scanf("%d",&arr[i]);
[Code] ....
[URL] ....
Which object's draw is being called?
I'm getting an error message that I can't seem to fix. The error clearly states that during the link aspect of the debugging and build there is an error that says that the stdio.h file is either missing, invalid or corrupt. When I try to program using any of the other headers I'm getting the same error. The files are there I can see them in the include folder, so I'm asking what can I do to fix all these headers and beware I am a beginner at programming and using any kind of compiler.
This is the error I receive.
1>------ Build started: Project: hello, Configuration: Debug Win32 ------ 1>LINK : fatal error LNK1123: failure during conversion to COFF: file invalid or corrupt ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped =========
This is the compiler I am required to use for an online course and all instruction is given for the Microsoft visual 2010 express edition. Also the only file I think that's being referenced is the #include <stdio.h>.
#include <iostream>
#include <stdlib.h> //used for random numbers
#include <time.h>
#include <string>
using namespace std;
int main() {
int bridgeWidth ; //set bridge width to any number
[code].....
I got this message after i delete allocated class object, should i check the deleting? if it's object what is the correct way to delete/delete[]?
theCars[nToDel] is a static array of pointers
bool Cars::deleteElement(int nToDel) {
if (theCars[nToDel] != NULL) {
delete[] theCars[nToDel];
theCars[nToDel]=NULL;
inUse--;
return true;
} else
return false;
}
I've been using a timer to refresh the listview on my application, but after half a second, I get the error message at first try/catch method in RefreshPlot() in PlotComponent.cs:
Quote An exception of type 'MySql.Data.MySqlClient.MySqlException' occurred in Marketplace.exe but was not handled in user code
Additional information: There is already an open DataReader associated with this Connection which must be closed first.
Basically I wanna make my textbox to contain only positive numbers. I was able to do that via masking and regex. I should let you know that the column is bound to a variable which is an int. Therefore, the user always have to type an int (no letters or characters). Like I said, I have been able to prevent user from typing anything but numbers.
Now to the problem:When the user leaves the cell blank and chooses to get out of that cell, they'd get "Input string was not in correct format" next to that cell.
-My approach is: whenever there is nothing in the cell, just replace it with 0. I have code that I thought will do that, but it wont. Seems like the cell was not null, because the if clause won't execute. This is the code:
private void gridView1_CellValueChanged(object sender, DevExpress.XtraGrid.Views.Base.CellValueChangedEventArgs e) {
GridView view = sender as GridView;
if ((view.GetRowCellValue(e.RowHandle, colPriority).ToString() == "") ) {
list.ElementAt(this.gridView1.FocusedRowHandle).priority = 0;
}
}
-Another approach is to change the display or the error message to like "Please enter a number." I have tried doing this but no luck. When I try this concept with the code below, it pops me a dialog box say "Do you wanna change the value?". I dont want it to pop up a dialog box. Also, i was looking for a message that I tried to give it. Looks like it doesn't even get in the if clause because I have checked. And its because its not null? I dont know. This is the code:
private void gridView1_ValidateRow(object sender, DevExpress.XtraGrid.Views.Base.ValidateRowEventArgs e) {
GridView view = sender as GridView;
GridColumn priority = view.Columns["Priority"];
if (view.GetRowCellValue(e.RowHandle, colPriority) == null) {
e.Valid = false;
//Set errors with specific descriptions for the columns
view.SetColumnError(colPriority, "Incorrect Value");
}
}
PS:I have checked that both of these methods get executed, so it isn't like they don't. I used some console.write stuff to check this.
Code:
#include<stdio.h>
void main
{
int i;
int marks[10];
}
[code]....
how to give error and ask user to re enter if user enter other then a number?