If I have an array and all I have is an upper limit on how big the array can get, and if the number of elements that get added can be considerably smaller than this limit, is it always the right choice to declare a pointer and just reallocate extra memory whenever the array grows? For instance, instead of declaring int a[max] I can declare a pointer int *a and than just realloc when I add elements.
View 1 RepliesI have function that looks like this myfoo(char* Name) Now i want to compare this name to another one . But the another name is a pointer . This my code :
bool Tribe::RemoveSurvavior(char *H_Name) {
const char *p;
p=SurpointArr[i]->GetSurvivor_Name();
}
I need to compare if p is same as H_Name.
Mine is do it with for on each element but when i use sizeof it gives me size of char and not real size of the name.
Design and implement the class myArray that solves the array index out of bound problem, and also allows the user to begin the array index starting at any integer, positive or negative. Every object of type myArray is an array of type int. During execution, when accessing an array component, if the index is out of bounds, the program must terminate with an appropriate error message. Consider the following statements:
myArray<int> list(5); // Line 1
myArray<int> myList(2,13); //Line 2
myArray<int> yourList(-5,9); // Line 3
The statement in Line 1 declares list to be an array of 5 components, the component type is int, and the componentst are : list[0], list[1]…list[4]; the statement in Line 2 declares mylist to be an array of 11 components, the component type is int, and the components are: mylist[2],…mylist[12].
This is what I have so far:
#ifndef H_myArray
#define H_myArray
#include <iostream>
using namespace std;
template <class myArray>
class myArray
{
public:
private:
return 0;
};
#endif
Code:
#include <stdio.h>#include <string.h>
int main() {
char pin [] = {1,2,3,4};
printf("%s",pin);
getchar();
}
the above code displays random symbols as opposed to 1234
Is there way to find the size of structure pointer size? When we tried to get the size of structure pointer will get size of address(@ location) which would be 4 bytes long. But I want to get the size of all structure members size using structure pointer.
View 1 Replies View RelatedThat code should make the size of the pointer (how many chars it can store) bigger but when i run it it show always 3 char positions while it should show N*M.
Code:
#include <stdio.h>#include <stdlib.h>
int main(void) {
int M, N, P, i;
scanf ("%d %d", &M, &N);
P = M * N;
char *c = malloc(P * sizeof(char));
[Code] ....
int hash = 0;
char *strings[100];
if((int)strings[i] != 0)
if((int) strings[hash] != 0)
while((int) strings[hash] != 0)
if((int)strings[hash] != 0)
if((int)strings[hash] != 0)
Here is an example,
Code:
class A {
public:
virtual void foo(){}
virtual void foo2(){}
virtual void foo3(){}
};
int main() {
A a;
int ret = sizeof(A);
return 0;
}
Basically object a contains a virtual table pointer which is of size 4 bytes. Since class A should have a virtual table which contains three pointers pointing to foo, foo2,foo3 separately. So the virtual table should be of size 12 bytes. I wonder where is virtual table located in memory?
I want the 'counter' loop to go through twice, each time reading in 15 characters from the standard input, then going through the evalutor
Code:
#include <stdio.h>
#include <ctype.h>
int main (void)
{
char inputtedhand[64];
int NumC=0, NumD=0, NumS=0, NumH=0;
}
[code]...
I've been making a project that requires different files to have access to objects declared in other files such that circular dependencies are created. I've done some research and discovered that pointers and forward declarations should be able to fix this.
Example:
File 1 declares variable x, must edit x and y
File 2 must edit x and y, declares variable y
I know this isn't the best example, as you could probably declare x and y in the same file, but please suffice it to say that I'm unable to do that in my project.
Im writing program for a rail fence cipher that should run from the command prompt and take in two .txt files, one containing the key for how many rails there should be (between 1 and 25) and the other containing the message to be encrypted. Both of those txt files should be entered from the command prompt, taken in with the program's arguments, not asking the user for input I think I have the logistics of how to get the program to encrypt it worked out, but every time I try to run the program it keeps on crashing.
The program should run when I enter this:./railcipher samplekey.txt samplemessage.txt
I'm pretty sure my issue lies within my first few lines of code, with the main(), or with the FILE*, but I dont know what I would need to change it to for it to work properly.
Code:
#include<stdio.h>
#include<string.h>
#include <stdlib.h>
int main(int argc, char **argv[])
[Code]....
So I have to write a step in my program that reads in up to 8 variables. Simple, but if the User submits an invalid value, I have to give an error message and ask him to re-enter the value until he enters a valid number. Here's my while loop that works perfectly:
Code:
while (true) {
printf("
Enter the mark given by Judge 1: ");
scanf("%f", &m1);
if ((m1 >= 0.0) && (m1 <= 10.0)) {
break;
}
[code]...
I'm not sure what to write in the else statement to make the programme understand that it has to repeat the exact same step but without adding 1 to index. Is this possible or do I have to suck it up and just use while loops instead? I'm very new to programming.
I'm trying to keep track of the size of blocks of memory that a pointer points to. No matter what I do, this code below always outputs the integer 8.
If I change 1000 to 5, I still get 8. If I change it to 0, I get 8... If I change it to -1, I get 8. If I change int *a to double *a, I get 8. If I take away the & symbol, I get 8. If I use *& instead, I get 8.
Why? I want it to output 1000. If I change that to 500, I want it to output 500.
int *a;
a = malloc(1000 * sizeof(int));
int j = sizeof(&a);
printf("%d", j);
I want to build my skills where I can allocate, inspect and change memory sizes.
I have the following details
double x= 1.5
double y= -1.5
int m= 20
int n= 4
my question is 5 * x - n / 5 at which what would n / 5 equal to, I think its zero since its integer division? or would the 5 be considered a real number?
i have been fiddling with pointers but I don't understand how the proper syntax is written when I want to acces an element of an array through a pointer to a pointer...The code is all mostly just random bs for learning purposes. I marked the problem "// THIS LINE"
Code:
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#define MAX_DATA 100
int find_average(char *iden, ...) {
[Code]...
This is a sample program that declares a Matrix as a structure with an array as a pointer to a pointer. The following program is supposed to store a matrix in the structure "_Matrix" and later print the matrix just entered but it fails giving me a "segmentation fault". The sample code is given below
Code:
#include <stdio.h>
#include <stdlib.h>
struct _Matrix {
int row_size;
int col_size;
int **mat;
[Code] ......
Write a program using user-defined function which accepts an integer array and its size as arguments and assign the elements into a two dimensional array of integers in the following format: If the array is 1,2,3,4,5,6, the resultant 2D array is
1 2 3 4 5 6
1 2 3 4 5 0
1 2 3 4 0 0
1 2 3 0 0 0
1 2 0 0 0 0
1 0 0 0 0 0
how to accommodate double-size:8 bytes in 4 bytes pointer in 32bit system.
View 1 Replies View RelatedI'm wondering if it is possible to pass a 2d array to a function where the size of the array is not known at runtime.
I've tried
function ( array[][6] ) ;
But the size of the array has to be constant so it cannot be declared later.
I've tried using a template but you still have to declare the size of the array at runtime. Is this even possible at all?
The only other way I can think of is using a dynamic 2d array but how to create one and manipulate it.
I have the following code :
Code:
#ifndef TDYNAMICARRAY_H
#define TDYNAMICARRAY_H
namespace Massive {
template<class T>
T **AllocateDynamic2DArray(int nRows,int nCols)
[Code] .....
I wish to know how to traverse or loop through a dynamic 2D array using pointer to pointer as returned by the code above. Like I would in a static T[20][20] 2D array.
I'm trying to put all of the words in a text document into an array but this text document is 2,138 kb, and when my program is crashing when I try to put it into an string array. Could the file be too big to put into the array?
View 2 Replies View RelatedHere is what I've tried:
int numbers[] = {8, 2, 0, 4, 100, 5};
for(int i = 0; i < sizeof(numbers); i++){
cout << numbers[i] << endl;
}
However the results in the console is: 8 2 0 4 ,What am I doing wrong? Am I using the wrong built in function or something? I googled this and one of the links that came up stated to just do something like
arrayName.size()
but that didnt work for me either...
[URL]
Also, I know that I just enter the size of the list manually, in this case make i < 6 but I still want to know if there is a built in function or something.
I am not sure why I am receiving the error message:
Error C2466: cannot allocate an array of constant size 0
When I run the code:
Code:
int s;
cout<<"Enter the size:
";
cin>>s;
int array[s];
C++ masters,
I am trying to sort an array of size 10. If I was given:
Code: int List[Size] = {29, 11,12,10,3,26,13,15,19,2};
I need the program to sort all the odd integers and put the even integers to the back of the array. Like so:
Index: 0 1 2 3 4 5 6 7 8 9
Value:29 11 3 13 15 19 12 10 26 2
And it returns the number of even integers in the List. In this case it returns 4. All I am given to start with is
Code:
int evensToRead(int* const List, const int Size){
//body
}
I remember in C++, when a dynamic array is allocated, the size of this array is stored right before the array in memory. Therefore compiler knows exactly how long, when this array is deleted.
Do all compilers store the size this way? Is it a safe method to get the size of a dynamic array?
Here is a example code, it works fine on Visual Studio 2012.
#include <iostream>
using namespace std;
class dummy {
public:
dummy() {
cout<<"dummy created"<<endl;
[Code]...
arrays with dynamic sizes. That being said, I'm working with a simple code which seems to work just fine, my only concern is that once I display the 'char array', not only displays the user's inputs but some extra data, symbols and what not.
why, if to my understanding the first user's input already sets the size of the array
#include <iostream>
#include <iomanip>
using namespace std;
[Code].....