I am not getting the real concept of delete operator. If it deallocates the memory, then why i am getting such output..!!
int main() {
int *a , b=5;
a = & b;
cout << *a << endl;
delete a;
cout << *a;
getch();
return 0;
}
Output:
5
5
We can't use the std::vector, std::map and std::lists implementations.
std::realloc doesn't call the destructor automatically.
If it is theoretically possible, we'll consider it and write lines similar to it, which should remain commented until something similar is possible.
int main(){
#define START 1000000000
#define END 10
unsigned int * array=new unsigned int[START];
delete[START-END]array;//Our suggestion to shrink the array
delete[]array;//Delete the array
return 0;
}
Suppose I have the following structure
struct b
{
char fullname[100];
char title[100];
bopname
};
and i declare a pointer to the struct as follows
b* bp;
and at runtime,
bp = new b[5];
In the end, is the statement delete[ ] bp enough to release the dynamically allocated memory. Or do i need to separately delete bp[0],bp[1]...
Does delete[ ] bp indicate that the array[ ] pointed by bp has to be deleted?? [I am confused as to how this happens, since the pointer only points at the 1st struct address]
We're trying to overload the delete[] operator with specific arguments. Which is the right way to call it? We use the GNU compiler and obtain compiler errors with all of these samples:
#include<iostream>
using namespace std;
typedef unsigned int P;
[Code]....
int main() {
int vnum = 0;
VEHICLE *vehiptr;
VEHICLE *dptr;
cout<<"Please enter the number of vehicle: ";
cin>>vnum;
vehiptr = new VEHICLE[vnum];
[Code] .....
How can I declare global 'delete' operation multiple times? Like, I've an implementation of global 'delete' operation in a file 'x' but I want a different behavior in file 'y'. However, if I override it again in file 'y' I get multiple definition error.
View 3 Replies View RelatedCan validate if my code implements the concept of insertion sort. The program is executing successfully. Just need a verification!
Code:
int i,j,k,a[100],n,num,min,max,temp;
printf("Enter array size: ");
scanf(" %d",&n);
printf("
Enter the numbers:");
for(i=0;i<n;i++)
scanf(" %d", &a[i]);
[Code] ....
Write a program using all storage class specifiers?
View 2 Replies View RelatedI would like to create program which will analyse bitmap so would need good concept to save data. I am interested about the theory and I realize that i must to think this carefully because bad concept could create insufficient memory or inefficient program. Basically I want my program work with HSV or HSL model so I would need to convert the bitmap to HSL, but I am not sure if I should convert it first and then analyse all pixels or should I start to analyse the bitmap and make the conversion to HSL during it. But my main question is what method to choose to save the data in memory.
Even that I would start with very small, it should work also with bigger image like image having 1200 or even 4200 px on height. So the program should first analyse all columns of pixels in the image so for example 1200x800 px image has 1200 columns. So I would like to know if is it possible to create such object which would have such structure like this
Obj->basicColumnData->black->columns[name]->group
and in the place of columns should be placed data for every column. I would look for groups of pixels in the column, so in the result the column x could bear e.g. 500 groups of information and every group should contain the range of pixels e.g. group 1 should contain y value from 0 to 20, group 2 should contain value from 25-27 and so on. So I would create 1200 columns bear many of groups. This would be contained in "black" or "white" member to contain the data. This is just simplified idea, but the whole object should contain next data not just basicColumnData... So there should be another members bearing information calculated from the selected data.
So my question is what kind of method of saving data use for this? Should I use heap and dynamic allocated memory or should I create custom class, which will define every member, but these members will have to be dynamic memory? With the dynamic memory is there problem that there could be not enough memory to create such big object?
Well, basically, what I've been doing was creating a class that would implement the concept of Double Linked List, but that would behave like a queue ( the STL implementation is deque, or Double Ended Queue ).
The problem occured when I have been trying to generalize the class using templates. I mean, why use only integers ? Why not double or char or what not ?
Worked perfectly before including all the template stuff..
// Source.cpp <=> Main.cpp
#include <iostream>
#include "DList.h"
using namespace std;
int main(void) {
DList<int> *list;
list = new DList<int>();
[Code] .....
The errors returned by the compiler:
Error1error C2955: 'Node' : use of class template requires template argument listc:usersjumperdesktopc++ otherdouble linked listdouble linked listdlist.h6
Error2error C2955: 'Node' : use of class template requires template argument listc:usersjumperdesktopc++ otherdouble linked listdouble linked listdlist.h6
Create an a simple Payroll Management Application using the concept of Binary Tree. The program will allow you to add, sort, view, search record. The application have also the capability to save and retrieve data in a file.
View 1 Replies View RelatedHow can I see the actual byte size of the pointer as output in the command prompt?
#include <iostream>
using namespace std;
int main () {
[Code].....
two things I did'nt get till now
Q->1 what is the actual use of function pointer ?
Q->2 what is use of passing function as an argument to another function ?
I'm a games/apps developer and right now I'm developing games/apps for iOS, Android and also PC / Facebook. I've also been working on C++ for some time but since I'm learning it all by myself, I still have some beginner doubts.
Is there any easy way to code a value conversion (for example an octal value to an actual number)?
I have a list of Strings that are passed to a method consecutively by reference from a class. I want to get the string value passed to the method at a point in time. The reason is to perform an if statement.
//this is the class that holds that holds the constants.
using System;
using Microsoft.VisualStudio.TestTools.UnitTesting;
namespace xxx.Functional.xyz.Login {
public class Constants {
public static String Username = "paul";
public static String Code = "4";
[code].....
With the loop below, is there a way to display the actual number without the leading zeros (scientific notation) or will it just display 0 since there are so many leading zeros?
num = 1;
while (num > 0){
num /= 2;
}
cout << num;
I have to manage a Clinic. I need to delete a booking (for example, if John said he's coming on March 22nd at 15:30 but then he say he's not going to come, I have to delete that booking so another person can use it).
idSearched: the id of the person that is not going to come. I have a lot of specialties and each one has a list. So I ask for the speciality to delete the node (the node contains John's booking). If I don't find it, I return (-1). searchSpecByID return a pointer to the list where the speciality is. So head will point to the first node of the list. In nodeToDelete I have the node I want to delete.
The program detects OK when is the first in the list and when not, but it doesn't delete the node.
Code:
typedef struct bookingList{
tSpecialty specialty;
struct nodo* intro;
} tList;
[Code].....
I'm doing a refresher for C++ and have gotten to operator overloading. I'm trying to perform an operator overload with the insertion (<<) operator, but I have encountered a problem.
Here's my class [In a header file "Shinigami.h"]
#include<string>
namespace K{
class Quincy;
class Shinigami{
friend std::ostream& operator<<(std::ostream&, const Shinigami&);
[Code] .....
If the operator function is a friend of the 'Shinigami' class, why doesn't it recognize any of it's private members? I need it to be in this file because I'm doing a bit of association with the 'Quincy' class.
I thought it was the namespace, but I included that.
I need to display 0-15 hex numbers[0X00-0x0F] in decimal value...& I'm getting the output but it's not exactly what it should be,below is my code.. [This not the complete code,but main part where the changes are done]
Actual output i should get is for 1v it should generate 0001,for 2v it should generate 0010 and simultaneously till [15v-1111]... But what i'm getting is exactly different to this for eg for 7v,8v&9v the bits generated are 1101,1011,1011 respectively...
[URL] ....
Code:
sbit V1 = P2^0;
sbit V2 = P2^2;
sbit V3 = P2^4;
sbit V4 = P2^6;
#define DAC_table V1,V2,V3,V4
#include <stdio.h>
#include <string.h>
idata unsigned int ptr2tbl ;
[Code] .....
Currently I am working on a program that will find the actual distance between two points on a grid. It also determines the angle of the line segment in degrees. Now, i need it to be able to find any other points on or near the line. It will be running in a loop to find each additional point sequentially until all the points have been plotted. Unfortunately, I am not entirely sure how this is done. So far, I think that I could develop an algorithm that converts the angle into a ratio of vertical movements to horizontal ones.
View 7 Replies View RelatedI have to convert string to double. i'm using "atof" function to achieve same.
I have string as "0.0409434228722337" and i'm converting with "atof" But i'm getting double value as "0.040943422872233702". Why it adds 02 additionally at the end?
More example :
"0.0409434228722337" converts to "0.040943422872233702"
"0.067187778121134" converts to "0.067187778121133995"
Is there any other possibility to convert string to double without changing data ?
I'm trying to use a listview component to show all the fonts on my system, and display each item (row) in the actual font design.
When I run the following code, nothing displays in the listview.
If I rem out line 4, then the list populates with all the fonts, but of course, in the default listview font.
I thought I read somewhere that each item in a listview can be set to a different font.
int i = 0;
foreach (FontFamily oneFontFamily in FontFamily.Families) {
listView1.Items[i].Font = new Font(oneFontFamily, 10);
listView1.Items.Add(oneFontFamily.Name);
i++;
}
Code:
Real x = (arg.state.X.abs - mViewport->getActualLeft())/float(mViewport->getActualWidth());
Real y = (arg.state.Y.abs - mViewport->getActualTop())/float(mViewport->getActualHeight());
_trace("%f %f
", x,y);
Code:
#include <Windows.h>
#ifdef _DEBUG
bool _trace(TCHAR *format, ...) {
TCHAR buffer[1000];
[Code] .....
Results:
f f
f f
f f
f f
How to display the actual values in the console?
I'm looking for a function like GetThreadTimes, but one that gives correct results in a hyperthreading CPU.
For instance, if you start 2 threads on a CPU with 1 physical core and 2 logical cores, GetThreadTimes will say that both these threads use 100% CPU.
However, in reality they only use 50% each. Is there a function that returns correct results, or is there another workaround?
#include <stdio.h>
#define MAX_USERS 20
struct {
char ID[10];
char Name[40];
int Pos;
[Code] .....
I was attempting something weired with address to move data around when I discovered that the size of the array is not what I expected. I am passing this structure as &Users to a function that declares it as a void *, then I can deal with chunks of data (memmove) and not have to worry about index or things like that. However...sizeof is returning something I do not understand.
I am beginner with C++ and I want to know. When do I use new and delete keywords? And what can I use them to do? Only thing I know about the new keyword and delete is that you can do this:
Code:
int Size = 5;
int *ptr = new int(Size);
cout << *ptr << endl;
delete ptr; And more . . .
But when do you use this keywords? I am just curios about them and want to now if them can be really effective to use.