C++ :: Assign Value Dynamically?
Jun 18, 2013I have array of pointers and when i tried to assign values dynamically all array items have the same value which is last value.
char* list[];
int DynamicDemo(void)
{
[Code].....
I have array of pointers and when i tried to assign values dynamically all array items have the same value which is last value.
char* list[];
int DynamicDemo(void)
{
[Code].....
This is my code , i should Assign value val to interval [keyBegin, keyEnd).
#include <assert.h>
#include <map>
#include <limits>
void assign( K const& keyBegin, K const& keyEnd, const V& val ) {
if(!(keyBegin<keyEnd))
[Code] .....
I am having some difficulties knowing how to assign city to the list.
Code:
class DestinationList
{
private:
int num;
// number of objects in the list
Destination list[MAX_CITIES];
// array of destinations
public:
[Code]...
How can we assign a pointer to a function? const char* function_name(), here what exactly does the pointer point to?
View 4 Replies View RelatedIm starting with C. Like I said in the title, how do I assign the value from a function to a variable? I mean I have this function:
Code:
int EnteroAleatorio(){
rand();
return rand();
}
and I would like to assign the value of EnteroAleatorio to a variable in my main function, but when I try to do it and compile, I got the next error: non-lvalue in assignment
Why would you ever assign a pointer to an existing array?Take this link for example. URL....I understand that pointers use dynamic memory allocation so they are much more flexible then a built in array, but if you already have an existing array, don't you already have static memory allocation for that array? Why bother assigning a pointer? Regardless of the pointer, doesn't the program still allocate static memory to the array anyway?
View 3 Replies View RelatedI have a silverlight app that uses TextBox XAML controls.
In the c++ code-behind, IXRTextBoxPtr types are associated with these textboxes using "FindName" like this:
FindName(L"ColNum3", &m_pColNum3);
(where ColNum3 corresponds with the XAML CODE like this: )
Then, the code assigns the pointer like this:
std::wstring wsTransfer; // gets the wstring from imput
const WCHAR * wpszInput;
wpszInput = wsTransfer.c_str();
m_pColNum3->SetText(wpszInput);
but the display does not show the text data.
What am I missing? What steps am I missing to have this text modification display on the screen?
Below assignation? It is a bit confusing.
myString = ""myInteger"is";
I am making a game Pong, and have been struggling with the collision aspect between the baal hitting off the paddle. I have created a Class, to draw a rectangle, to work with collision however I dont know how to assign the rectangle to the images of the ball and paddle.
#include "stdafx.h"
#include <iostream>
#include <time.h>
#include <vector>
#include <cmath>
#include "gwin.h"
const int NUMBEROFBALLS = 1;
[Code] .....
If I have a one-dimensional array of length 10, vector<int> x, and I want to assign all the elements to value 5, then I can do the following:
Code:
vector<int> x(10);
x.assign(10, 5);
(I can also do this in x's constructor, but in my scenario I want to repeatedly assign x's elements in a loop, without having to construct a new vector in memory each time.)
If I now have a two-dimensional vector, vector<vector<int> > y, and I want to assign the first vector to length 20, the second vector to length 10, and each element in the second vector to value 5, then I can do the following:
Code:
vector<vector<int> > y(20, vector<int> (10));
for (int i = 0; i < 20; i++) {
y[i].assign(10, 5);
}
But is it possible to do this without the loop? Can I make the two-dimensional assignment in just one line, in the same way that the one-dimensional assignment was made?
Perhaps it would like something like the following, which is not correct but illustrates what I mean:
Code:
y.assign(20, assign(10, 5));
Another way of doing this would be the following:
Code:
y.assign(20, vector<int> (10, 5));
But wouldn't this cause the memory in the second array to be dynamically allocated each time? I don't want to do this - I want to keep the same memory, but just assign the elements to 5.
I'm trying to learn how to assign bit widths manually to numbers. Here's my code below:
Code:
#include <stdio.h>
struct node {
unsigned long x : 53;
[Code].....
And I get the following complaint from the -Wall compilation flag, " warning: format '%lu' expects argument of type 'long unsigned int', but argument 2 has type 'long unsigned int:53' " which is talking about anna.z, to be specific.
How do I add field width to printf?
See the simple code below. The compiler gives message:
assigning to type "char[20]" from type "char *".
I've tried everything else that seems reasonable but none works. How can I assign string Hello to the structure member?
Code:
int main() {
struct strc1
{
char msg1[20];
char msg2[5];
}
talk;
talk.msg1 = "Hello";
}
I have this code:
Code:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
[code]....
What I want is basically to assign to the *p the pointer of the string so that i could do the following printf(" print string %s",*p); so i dont know how to do that.
When I try to assign strings to a double pointer, it only prints out the last string when I try to print everything out, and then it segfaults.
Code:
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
main(){
char **test = calloc(3,sizeof(char));
[Code] .....
Am I assigning something the wrong way? Also, I am trying to avoid using array notation in order to practice, at least for the assigning of the strings.
I have to ask system (linux) for a value and then assign it to the variable.
Example:
unsigned char date[] = system("date");
Of course this is wrong, but illustrated what is my goal.
How to achieve this effect ? I've heard about POSIX but how to include and use it.
I'm a C beginner trying to assign struct member values to other struct members to create a list.
I've tried dot notation, pointer notation, strcpy, memcpy, memmove and normal assignment.
Nothing has worked.
cust_list.h
How to assign numbers stored in a buffer memory to a 2D array.
The data type is unsigned 16bit (unsigned short) integers and they are stored in a 16bit/2bytes*1280*1024=2621440 bytes memory. The pointer pBuffer is the starting address of the buffer. Now I initiated an array and then assign the numbers to the array.
Code:
unsigned frame[1280][1024];
for (int i=0;i<1024;i++){
for(int j=0;j<1280;j++){
frame[i][j]=(*(unsigned short*)pBuffer+1024*i+j);
printf("%u ", frame[i][j]);
}
printf("
");
}
Because I know the number in the memory, I know after running the code that the result gives me nonsense.
I tried frame[i][j]=(*(unsigned short*)pBuffer+1024*2*i+2*j);
Since I think the pointer needs to move 2 bytes at a time, but it still gives me nonsensical array back.
Am I using the wrong expression to assign the values?
Assign value of pow(2,800) to char array or string ....
View 1 Replies View Relatedtypedef tr1::unordered_map <string, pin *> pin_cmp;
pin_cmp _pin_cmp;
_Pins[_num_pins] = new pin (pin_id, _num_pins, s, n, d);
_pin_cmp[_Pins[_num_pins]->get_name ()] = _Pins[_num_pins]; //performance profiling
What actually the code doing?
_pin_cmp[_Pins[_num_pins]->get_name ()] = _Pins[_num_pins]; //performance profiling
I am not familiar with unordered_map which still can use with array[].I am confuse unordered_map just need key and value why will have array[]?
this is the first time to ask my question on Cplusplus. my qustion is i got this message when i trying to run this code:
object.h
#ifndef __NCTUNS_nslobject_h__
#define __NCTUNS_nslobject_h__
#include <stdio.h>
[Code].....
so, my problem is when the compiler starts compiling it stops on this code :
NslObject::newKeyPair (RSA::GenerateKeyPair(keyLength));
and the appeared message is :
Error:
object.cc: In function ‘void Set_KeyPair()’:
object.cc:53: error: no match for call to ‘(KeyPair) (KeyPair&)’
so, how could i assign a generated keypair class value to NslObject::newKeyPair.
I am writing a math program, using variables of type double, and had initialized all variables to 0.0.
I now realize that not all results will be valid.
Is there a way to explicitly assign a variable of type double a non-numeric value, for example, "NaN", "Undefined", or "Unassigned" or something like that?
That way, when I read through the printout of results, I will realize the "NaN" results indicate a valid solution was not found. Whereas a 0.0 might not stand out.
I'd hate to have to go back and delete the initialization, and then re-assign 998 values just for the sake of 2 non-solutions.
If I have a struct of some vector members, like
struct {
vector<double> a;
vector<double> b;
vector<double> c;
// ...... continue
} struct_test
How can I assign a value (push_back()) to all the vector members simultaneously, instead of do it one by one?
I am using boost matrix for generating matrices used for filters. I wan to assign a pointer to these matrices so i can call them out of the function. but i am not able to understand where i am failing. the example code is here.
int main(int argc, char *argv[]) {
QApplication a(argc, argv);
identity_matrix<double> M(3);
std::cout<<M<<std::endl;
[Code] ....
I wrote this code but it opens file in its folder Iwant to save in somewhere else. How I could assign path for the files in for loop?
for (double j = 0.5; j < 1.4; j+=0.1) {
s +=1;
stringstream a;
a << j;
filename = "Vzcr_" + a.str();
filename += ".txt";
files.open(filename.c_str(), ios::out);
So I'm working on program I had in Windows Form Application.
I have a combobox that lists the years 1981-2013. Beside it, a simple Enter button.
I wanted to be able to assign individual lines of text to each year that would be displayed in the message box.
Like if the user selects 1981, clicks Enter and the message box displayed "In the year of 1981.." but if they select 1982, the message box displayed "In the year of 1982.." I have everything else I want working, except that I can't figure out how to assign different lines of text to different years.
I can assign values to pointer character array like this...
Code:
char *array[4]={"abc","xyz","dgf","sdt"} ;
but the case is i don't know how to assign strings through key board ???? with using gets ,getchar or other suitable function