#include <iostream>
using namespace std;
void myfunc(int* ); // what do i put in these parameters to accept a mem loc of a pointer
int main () {
int x = 5;
[Code] .....
SOLUTION:
#include <iostream>
using namespace std;
//Purpose to create a function that returns a pointer to a pointer
int** myfunc(int**);
int main () {
int x = 5;
[Code] ....
Is there such thing as passing a winforms label by reference? For example, can I create a pointer label and pass the address to a function? I've looked online but couldn't find anything. Perhaps that's a sign?
View 1 Replies View RelatedSem is a pointer to semantic which is a struct type variable. I pass the sem into function yylex so i can fill the semantic.i and semantic.s(s points to an array). The problem is that when sem->i = a; is used inside yylex function, sem->s stops showing to the array.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <iostream>
using namespace std;
union SEMANTIC_INFO
[Code] ...
i need to pass myboard.board (board is in the class Cboard and it is an array of int) to a function in a class called piece however this is troubling . i need to pass it as pointer os that i could change its value here under is my code.
main.cpp Code: #include<iostream>
#include"board.h"
#include "pieces.h"
[Code].....
I'm having a problem understanding something with pointers. I was trying to pass a pointer into a function in MSVC-2013, like
char* charptr;
and then calling
myfunct(charptr);
and then inside the function i would set charptr equal to another char ptr, simply like
charptr = anothercharptr;
But this actually caused a compile failure in MSVC, saying charptr is being used without being initialized. in Code::Blocks it just gives buggy output.
I solved this issue by calling the function like
myfunct(&charptr);
and declaring the function like
myfunct(char**);
and then I had to dereference the charptr in the function when assigning it to another ptr, so
*charptr = anothercharptr;
It seems like you should be able to just pass a ptr into a function and change its address to that of another pointer? My main question is really, what is the value of a pointer? I thought the value of a pointer was just the memory address it contains. But then I had to reference it to pass it into the function.
What is the difference between the value of the char* charptr written as either charptr and &charptr?
I don't understand how my code not run.
#include "stdafx.h"
#include<iostream>
using namespace std;
struct student{
char name[30];
char birthday[20];
char homeness[50];
float math;
[Code] ....
void extf(int a) { }
template<typename P>
struct A {
// 1
template< void (*F)(P) >
static void call(P arg) {
[Code]...
Why it is not working? What would be a proper way to pass function pointer as a template parameter?
I am trying to create a callback system for input events in my game engine.
Here is a cut down version of the EventManager.h file
#include "Controls.h"
#include "Object.h"
enum MouseEventType{PRESSED, POINTER_AT_POSITION, PRESSED_AT_POSITION };
[Code].....
This works if the function pointer being passed to the event manager is not a member function.
I have two other classes Scene and Object that could potentially use this EventManager to create callback events. Scene and Object are both pure virtual objects. How can I pass a pointer to a member function of the child classes of both Scene and Object? I am fine with just having two separate watchEvent functions for Scene and Object but how do I pass the type of the Object or the type of the Scene? The child classes are unknown as they are being created by someone using this game engine.
For example, if I want to make a player object it would be something like
class PlayerObject : public Object{...};
Now that PlayerObject type has to find its way to PlayerObject::functionToCall(). I think I need templates to do this but, since I never used them before
This is how I intend to use this
class OtherScene : public Scene{
void p_pressed(void){
//pause
}
[Code].....
I am trying use a print function to print out data in a struct. My questions are:
1. I have to use pass by reference. For the print function, I am passing the struct pointer as a reference, however, I don't want the print function to accidentally change anything. How can I make it use const to ensure that?
2. The deleteprt function doesn't look right to me. I feel like it should just be delete ptr not delete [] ptr.
#include <iostream>
#include <fstream>
#include <iomanip>
#include <cstdlib>
#include <string>
using namespace std;
struct Inventory {
[Code] .....
#include <iostream>
using namespace std;
struct node
{
[Code]....
How is this not working? just the add & display function.
I am doing a piece of gui code on some embedded system.
I'm trying to find a way of eliminating the local variable kEvent:
Code:
EVENT kEvent;
....
Code:
kEvent = EVENT_UPSTREAM;
xStatus = xQueueSendToBack(getEventProcessorQueue(),&kEvent, 0 );
....
I tried this, it doesn't work:
Code:
xStatus = xQueueSendToBack(getEventProcessorQueue(),(EVENT *)EVENT_UPSTREAM, 0 );
Shouldn't this work?
Why do we not pass the address of the string during printf or scanf functions like we do for Integer or float variable types?
View 2 Replies View Relatedi really don't know why has a error in my code, that pass a pointer of pointer (name of a matrix with 2 dimensions). Here is the source code of a simple example where appears segmentation fault when execute (but compiles normal):
#include <stdio.h>
#define LINHAS 3
#define COLUNAS 5
float a[LINHAS][COLUNAS];
void zeros(float **p,float m, float n){
int i,j;
for(i=0;i<m;i++)
[Code]...
I've got a problem with a piece of code that it doesn't seem to work anymore.
Code:
#include <stdio.h>
#include <conio.h>
main () {
[Code] ..... i
I chose a to be 5 and it displays the following:
"Type a value for a:
5
5 in octal is: 5
5 in hexadecimal is: 5
Process returned 23 <0x17> execution time : 1.031 s".I first saw this when trying to display the address of a pointer. Am i missing something? I used to run this code on dev-c++ successfully but after a day or so of practice, it's not working anymore. I switched from dev-c++ to code blocks.
I have a pointer to an Address is there a way to save that address value (not the content but the actual address) into a char ?
View 5 Replies View RelatedI have the following code.
StackElement *StackElementArray;
StackElementArray = new StackElement[iMaximumDepth];
I want to assign one element of this array StackElementArray the address of another object. For example,
voidStackMem::push(StackElement &iStackElement) {
CurrentDepth++;
StackElementArray[0] = iStackElement;
}
The StackElement class contains pointers to some dynamic arrays. When I use the assignment, StackElementArray[0] = iStackElement;, it doesn't copy the complete contents and I have to define an 'assignment operator' function to copy all the contents. I am wondering if there is a way I can assign StackElementArray[0] the pointer to the StackElement object. In that case, I will not need to copy the contents of iStackElement into StackElementArray[0] and will just copy the address.
What I'm trying to do is:
int *p;
someType memoryLocation;
cout<<"Enter your memory location: ";
cin >> memoryLocation;
p = memoryLocation;
cout << *p;
I was just messing around with some code, and was curious to if this was possible.
Why my pointer skips over the colour addresses, it jumps to the next size address when I use Pointer++. I have tried changing the the char array to 4 bytes instead of 32 and whatnot but it doesn't work.
If I set the Pointer = the first colour address, it skips over the size addresses and only get the colour addresses. I know using 2 arrays would easily solve everything, but sadly I must use only 1.
I'll post whatever relevant code here:
For part of my program in class I have to take a pointer address and determine if it is equal to 0 modulus 16. But I can't figure it out.
View 1 Replies View RelatedI need to initialize a pointer variable with a knowing address. See code below, ptr is the final destination and value of ptr_address contains the address value, so I need to do something like ptr = *ptr_address.
Code:
int *ptr;
int *ptr_address;
int address;
address = 0x10000005;
ptr_address = &(address);
ptr = *ptr_address;
The problem is that compiler gives the following warning message:
warning: assignment makes pointer from integer without a cast [enabled by default]
Is my code wrong or there is any other way to do it without receiving this compiler warning?
I have an integer pointer and i want its address without allocating memory,
main() {
int *a;
cout<<a;
}
This is giving 00000000 and its but obvious. Now if i use address of a (&a) along with *a,
main() {
int *a;
cout<<a;
cout<<&a;
}
'cout<<a' gives me a constant address but 'cout<<&a' gives me different address.
what is the reason behind & and why behaviour of 'cout<<a' changes when using with &.
I get a run time error saying something about memory locations when I run this program.How can I make this program work using pointers?
//this program converst miles to km
#include<iostream>
#include "std_lib_facilities.h"
[Code]....
//program to form a header file
/* using pass by reference in pointer */
#include <iostream>
#include<math.h>
[Code].....
How can I add the variable adress to a void pointer inside of a class?
class variant2 {
private:
void *Vvariant=NULL;
public:
template<typename b>
variant & operator = (b *adress)
[Code] ....
if possible i want avoid the '&' when i assign the variable address.(variant2 f=varname;//like you see i don't use the '&')
for the moment i just need put the address to Variant pointer. but i receive several errors .
I'm having an issue coming up with an if() statement to check if a word match the one in the value of a pointer's address. So far the best I've come up with only matches the first letter of the words, you'll find it in the code below.
#include"Header.h"
int Colour(struct MyStruct *ArrayPointer, int ArraySize) //ArraySize = 3 for this run. {
int ColourCount = 0;
for (int i = 0; i < ArraySize; i++) {
[Code] ....
An example run you can see in attached pic.
I want to have an if statement that only accepts "Red" and not the occasional "Ravaged_Anus".
I'm using MVS Express 2013, .c source files, and the C++ compiler.
Attached image(s)
What is the difference in pass by pointer and pass by reference? As per my understanding, there is no difference much.If a function accepts pointer, then NULL check can be performed.other than this i'm not able to see any big difference..
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