C++ :: How To Insert Array Size As Variable
Nov 30, 2013How do I insert a array size as variable?
View 5 RepliesHow do I insert a array size as variable?
View 5 Replieshow to insert a variable for the size of array and prompt user to insert the elements for the array?
View 13 Replies View RelatedThis problem is best explained by looking at its output below. I stored 15 different values but when retrieved some are wrong.
#include <iostream>
using namespace std;
class A {
public:
int ** pointer;
[Code] ....
I need to store and retrieve the 15 different values correctly. How to solve this? The main thing is, I need to store the pointer in class A objects.
The WinAPI has a struct like this for raw input:
Code:
typedef struct tagRAWINPUT { RAWINPUTHEADER header;
union {
RAWMOUSE mouse;
RAWKEYBOARD keyboard;
RAWHID hid;
} data;
[code]...
The definition of the struct doesn't show it but the documentation says that bRawData is variable length. sizeof(RAWINPUT) will not be the correct size when the data field is of RAWHID type so how do you allocate a variable with automatic storage type that has the right size for the entire struct? You can get a header that has the size for the entire struct but how do you actually allocate storage space for the data without using malloc? I've seen some example code that used a char array but that violates aliasing rules and there are also alignment issues with that approach.
I am wondering how I could make an array which contains arrays, but with a variable size.My first try..
Code:
int array[][] = {{1}, {2}};
But this isn't proper
I have a function like this
void foo( int i) {
...
uint8_t buf[ i];
...
}
And I don't understand why the compiler is not complaining... I'm using g++ -c -g -Wall to compile ....
I am new to C. I've been trying to use C to code some statistical functions originally coded in R. I've encountered an interesting phenomenon. In the function foo1, I declared the array v1v2b using an actual value 1999000. The function runs fine when I call it in R.
Code:
void foo1(double *x, double *y, int *nsamp){
int i, j, k, oper=2, l;
double* v1v2=malloc(sizeof(double)*((*nsamp)*(*nsamp-1)/2 + 1));
outer_pos(x, y, nsamp, &v1v2[0]);
double v1v2b[1999000]; //<-------HERE
for(i=1; i<= 1999000]; i++){
v1v2b[i-1]=1;
} }
However, in foo2, I first create an integer variable called index, and store the value 1999000 in it. I then use it to initialize the same array. When I tried calling this function in R, it either led to a stack overflow error, or completely crashed R.
Code:
void foo2(double *x, double *y, int *nsamp){
int i, j, k, oper=2, l;
double* v1v2=malloc(sizeof(double)*((*nsamp)*(*nsamp-1)/2 + 1));
[Code] .....
For my default constructor I need to set an array of strings to null and the size variable to 0. Here is my code for that
DynamicStringArray::DynamicStringArray() {
*DynamicArray[]=NULL;
size=0;
}
When I try and compile it I get an "expected primary expression before ']' token" error.
How to approach this? Not very clear on how hashing works..
Insert the following numbers into a hash table of size 10 (ie an array with 0…9 index position) using a hash function h(k)=(k*71+94)%10 and using Linear Probing.
75, 98, 43,1,-56,93,101,34,23
Insert the following numbers into a hash table of size 10 (ie an array with 0…9 index position) using a hash function h(k)=(k*71+94)%10 and using Chaining.
75, 98, 43,1,-56,93,101,34,23
I would like to create a table but I dont know how big. Thats why I want to use variable to describe its size. Something like that:
int x = 5; //I will use a function to set x
int Table[x];
What should I do to make it work?
I've been trying to store the inital size of a list in an int variable, so I can access it later in case I modify the list size. For example, I did the following:
std::list<AType *> myList;
myList.push_back(anATypeobject);
int initListSize = myList.size(); //initial list size
myList.push_back(anotherATypeobject);
myList.push_back(yetanotherATypeobject);
while(myList.size > initListSize)
myList.pop_back();
What this is supposed to do is to get an initial size of a list, and then be able to return to that initial size. However, when I try to do it in my code, initListSize always change if myList.size() changes. Is there a way to change that?
How to insert strings into an array of type char and also delete strings from that char array.
View 4 Replies View RelatedI am supposed to make a histogram. I succeeded in generating the integers for the histogram. But what I want to do is instead of displaying numbers in the console, I want something like "*" displayed for every integer there is in an array. It should look something like this.
*
****
*****
********
**********
******
****
***
*
As far as I understand, in some way I need to identify the integer in the array and for every single one of them I need to insert the symbol. I don't know how to identify it.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace ConsoleApplication1{
class Program {
static void Main(string[] args) {
diceHistogram();
[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
I'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'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].....
char A[]={}; this is the array in c++ of unknown size, now I want to enter some alphabets via loop and want to be the no. of elements i entered the size of the array. .
View 8 Replies View Relatedhow declaring this: { {1, 2}, {1, 2, 3} } Both outer and inner array had known size.
View 19 Replies View Relatedto return the array i shall make a pointer function thats ok.. but how do I get the size return if i dont know the size?
if I need to make AXB=C and output C my new array doesnt have a size..
The instructions call for the user to define the size of the array and all I have ever done is use a predefined size for the array and then let the user fill it. Here is what I have so far:
Code:
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
void Display (void);
void random (int *, int);
void Ascending (int *, int);
void Descending (int *, int);
[code]....
I am creating a class that has a private array on the heap with a constructor that takes the size of the array and initializes it on the heap. Later I have to make a deconstructor delete the space and print out free after.In my code, I was able to heap a private array and make a deconstructor, but I don't know how to take the size of the array and initialize it on the heap. My guess is this:
int* size = new int();
Also when you initialize size on the heap, don't you also have to delete it too? If so, where, in the code, do you do that? Here is my code so far.
Class Student {
private:
int size;
int* array = new int[size];
public:
Student(); // Constructor
~Student(); // Deconstructor
[code]....
How do you make a constructor that takes the size of the array and initializes it on the heap
Student::~Student()
{
delete[] array;
cout << "Free!" << endl;
}