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hinomotoblade · Dec 16 '11, 01:43 AM

Hello there, until now i am still confused about this one, i mean what for we cast the child class to parent class?.. since child class can access all of the member of the parent class, yeah since its has public modifier..

And also, we can cast the parent as a child using dynamic_cast right?.. but what for?..

I still relly confused about pointer interaction, why we need access the pointer thingy..

Thx...

Gregosky · Mar 31 '11, 03:40 PM

Hi guys,

I have written a library that manipulates data stored in double arrays. It took months to fine tune it and here it is, working fine. Everything was great until I started integrating my project with another open source project that uses float arrays. I need to pass my double arrays to the function that requires float arrays.. I am out of ideas how to do that.. I would like to avoid re-writing my project to use float instead...

Liam Kurmos · Feb 11 '11, 12:00 AM

A constructor to a class takes some arguments including a pointer which is assigned to a class variable. The constructor then calls a default constructor, but inside the default constructor the pointer is no longer valid.

some code should illustrate.

Code:

Feature::Feature(){
    cout<<"at b "<<oc<<endl;
    cout<<"b is "<<oc->geoSphere->getNumVs()<<endl;

...

Liam Kurmos · Feb 8 '11, 10:38 PM

im using g++ on ubuntu 10.10

i have a pointer to a vector of pointers to objects and i want to call a method on each of those objects.
oc->features is defined as:

vector<Feature* >* features;

i have to do:

Code:

vector<Feature*>::iterator it;
    for (it=oc->features->begin();it!=oc->features->end();it++){
        
        Feature* a=*(it);

...

vineesh vs · Jan 14 '11, 05:20 PM

Code:

#include<stdio.h>
#include<stdlib.h>
int **array();
 main()
{
  int **result=array(),i,j;



  //display result
for(i=0;i<2;i++)
  printf("\n");
	  for(j=0;j<2;j++)
	    printf("%d \t",result[i][j]);

}




//function
int **array()
{

...

AlarV · Jan 7 '11, 10:03 AM

Hey everyone, I created a GUI project, where I'm using a JTree. When it's created everything is ok, but in my run() method when I call it i get a nullPointerExce ption. Here is the code.

Code:

treePanel = new javax.swing.JPanel();
DefaultMutableTreeNode top =
        new DefaultMutableTreeNode("blah");
        mytree = new javax.swing.JTree(top);
javax.swing.GroupLayout treePanelLayout = new javax.swing.GroupLayout(treePanel);

...

Shane Fitz · Nov 30 '10, 05:47 PM

I am getting a warning and a common error in my code, and I need help understanding them.

The warning is:[Warning] assignment makes pointer from integer without a cast

Here is the code that i get the warning from:

Code:

line1 = biset_new(MAX_STRING); 
	line2 = bitset_new(MAX_STRING);
	bitset_un = bitset_new(MAX_STRING);
	bitset_in = bitset_new(MAX_STRING);

the left hand of...

Daryl Lee · Nov 20 '10, 09:12 AM

I'm currently coding a for fun version of a texture transfer tool from a paper i read from SIGGRAPH'01..i' ve figured out most of the coding based on the C# i found somewhere but I'm having trouble with its conversion into VB.NET.

my line

Code:

Dim ptr As Pointer(As Byte) = CType(CType(bmpData.Scan0, Pointer(Of System.Void)), Pointer(Of Byte))

returns an error that says Pointer is not defined (BC30002)....

Jose Diaz · Nov 17 '10, 07:07 PM

In the past couple of days i have noticed that a lot of people are having problems casting from one data type to another specially from void to char or int.

First of all void* just means that the variable can pretty much hold any type of data, from character all the way unto float. Let me just show you >>

Lets say you want void *variable;
to be equal 100;

Code:

void *variable = 100;

Now...

szidijani · Nov 15 '10, 04:03 PM

Hello!

I have a homework for tomorrow, and I simply can't solve it.
I have a list (with template) class, I wrote and it has an operator:

Code:

T& operator[](int i)
    {
        ToFirst();
        for(int j=0;j<i;j++)
        {
            StepForward();
        }
        return Act->value;
    }

For using the elements with indexes.
And I've...

Rizladonovich · Sep 19 '10, 03:26 AM

I am currently reading/learning c. I often like to look at code while I read, - to see more practical use then often are feasible in educational books.

I am looking at some code from wget.

Code extracted from wget.

Code:

/* file: mswindows.c */
void
windows_main (char **exec_name)
{
  char *p;

  /* Remove .EXE from filename if it has one.  */
  *exec_name = xstrdup

...

David727 · Jul 30 '10, 03:25 PM

#include<stdio. h>
char garb;
FILE *f ,*g;

int main(){
f=fopen("try1.t xt","wt");
g=fopen("try2.t xt","wt");

printf("f is equal to %ld\n",f);
//the result is 2009464032

printf("g is equal to %ld\n",g);
//the result is 2009464064

//I...

livesinabox · May 28 '10, 08:40 AM

I am a student and I am having trouble understanding Dynamic Memory Allocation and the usage of Double Pointers.

Code:

int **A

A=(int **)malloc(r1*(sizeof(int*)));

for(i=0;i<r1;i++)
A[i]=(int *)malloc(sizeof(int)*c1)

In the above snippet r1 and c1 refer to the number of rows and columns of a matrix A.

My question : What does the malloc function do here? I know malloc()...

miner · May 7 '10, 12:59 PM

Hi all

I'm doing my first steps in C and I need some help plz.

I have 2 structs, a node* and a stack*. I want to write a push() function that accepts to arguments, the node to insert and the pointer to the the top of the stack.

This way it works without problems: push(node *theNode, stack *theStack)
The call looks like that: push(newNode, newStack) and inside the function I can access the pointer...

rorybr · Apr 24 '10, 09:41 PM

hi,
i'm trying to import an unmanaged dll into a c# application. The dll is given to me but i'm new with dll import thing and having some troubles importing it. Dll comes with a pdf file which describes the functions but all parameters and types are c++ type and i need to write them as c# types. i tried "Dllimport" but i think i couldn't write the correct parameter types. Functions use handles and pointers which doesn't make it easier...

Search Result

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