C/C++ :: String Out Of Bound - How To Initialize Array
Mar 7, 2014
I'm a newbie to C++ and I am writing a code that searches strings and checks their value. I'm mostly working with if statements.
My code tends crash on Dev C++, even when I haven't recently saved any changes or compiled it, citing "memory access errors".
I recompiled in visual studio, and visual studio told me I have string out of bound errors.
My code is very long... but most of it is copy and pasted with slightly different conditions.
I believe the problem lies in how I initialize arr[4] ??
#include <cstdlib>
#include <iostream>
#include <string>
#include <sstream>
using namespace std;
int main() {
cout << "Hall symbol -- generator matrix program" << endl;
// Setting up a data structure bc a normal array cannot handle the data for the spacegroups
I am currently practicing designing classes. In one exercise, I am trying to store 15 words in an array, and randomly print one (using the rand() functions and seeding it with crime. I have a header file, a respective .cpp file, and a main .cpp file. When I try to compile the code using g++ GuessWord.cpp UseGuessWord.cpp -o UseGuessWord, I get the following error in my constructor: expected primary-expression before ‘{’ token
Is it generally better to initialize string data members as nullptr or as a zero-size array?
I can understand the former is superior from a memory-use perspective and also not requiring the extra allocation step. However, many string management functions will throw an exception - wcslen for instance - if you pass them a null pointer. Therefore I am finding any performance gained is somewhat wiped out by the extra if(pstString==nullptr) guards I have to use where it is possible a wchar_* may still be at null when the function is called.
This is an assignment question In C++, there is no check to determine whether the array index is out of bounds.Design a class myArray that solves the out-of-bound array index problem and allows the user to begin the array index starting at any integer, positive or negative. Every object of type myArray should be an array of type int.
Part 1 processes only int arrays. Redesign the class myArray using class templates so that the class can be used in any application that requires arrays to process data.
I don't understand the second part. should i just change the array from int to char or something?
Example : Code: struct x { int v[4]; }; const x test = { 0, 1, 2, 3 };
Why can I do this? How does the compiler know to write to this in the proper way? I get that v would be contiguous. Does that have something to do with it?
I am trying to initialize an array of pointers to an array of characters, I can do it in 3 lines but I really want to do it in one line at the same time keeping the #define.
imagine you have a world class. Than you have a tile class. Now, in the world class is a array with a lot of tiles and I want to initialize them with my imagination(For example I want a grass floor). But how I can do this, the array can only be create with the standard constructor. But it would be stupid and not very fast, that the tiles are first initialized with the standard constructor and than overridden to build the world. Whats the best way to initialize such a array ?
The data source of my grid is a list. Lets call the list list<objectX> listC where objectX is the type. objectX looks like this (this file cannot be edited):
public string otherProp1 { get; set; } public double otherProp2 { get; set; } public TimeFrameV endTimeframe { get; set; } public double otherProp3 { get; set; }
[Code]....
I have 4 columns bound to fields in objectX. Two of which is bound to TimeFrameV objects. Initially endTimeframe and startTimeframe were strings, but not anymore. I have been using "FieldName" property to bind the fields.
I want to access all three fields in TimeFrameV. I have a method FormatTimeFrame(TimeFrameV timeFrame) that takes TimeFrameV object as a parameter and returns the desired string result depending on the variable values in the object. Here is what I want, i want/need to somehow pass Fieldname property value. But it's a string and I am not sure if I can parse into int TimeFrameV object.
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
Need a C++ constructor to initialize each members of an array. how to give value for for each elements of an array declared as a class object according to the users input.
I tried in internet but am unable to know the differences. I want to know the difference between those two in terms of run time and compile time. Explanation required also for below one. Is this run time or compile time? How does we actually decide which is run time and which is compile time!
I've got an error saying that there is an access violation at 0x0000040 error no 0xC0000005
I've searched the net, saying the error may be due to an uninitialzed variable.I debugged the code, and found out that an object created from directx D3DXMATRIXA16 is uninitialized.With values ??,??,?? in each element
pMeshContainer->pBoneMatrices = new D3DXMATRIXA16[g_NumBoneMatricesMax];
here, pMeshContainer is a variable passed into a function called GenerateSkinnedMesh by pointer
when the method CreateMeshContainer finished execution, the meshContainer is passed back to its parent like this
*ppMeshContainer = pMeshContainer;
The whole meshContainer stuff is stored persistently inside the frame root wrapped within a class called CMesh So in that process, I haven't initialized pBoneMatrices in anyways. But what and where is the best way to initialize an array of DirectX9 objects.
There is a function called
D3DXMatrixIdentity(&...);
But how can I initialize each one of them with this call?
Notice that pMeshContainer->pBoneMatrices does contain a valid address, despite the fact that the elements inside it are never initialized...
Code: #include <stdio.h> #include <stdlib.h> #include <string.h> int main(int argc, char *argv[]) { int i; int arr[3];
[Code] ....
Notice we didn't set a value for second index but it returns 0. Should I assume that when declaring an array with n values, those values will be initialized to 0 automatically or should I still initialize the array with all 0s doing something like this:
Suppose I wished to initialize a dynamically allocated array of integers to zero. Would I do better to use calloc() or malloc + iterate over all entries setting each to zero? Which one is regarded as a better approach?
I am trying to initialize a 2D char array of strings into POSIX shared memory to be shared between 3 other processes. There are plenty of tutorials on how to use a pointer to share a single string or an integer between processes, but I could find no examples on how to initialize 1D or 2D arrays using mmap(). I have posted what I have so far below. It is the first program, which creates the shared memory object and initialize the array char files[20][2][100] with the value files[0][0][0] = ' '. What is the proper method to initialize and share an array in C?
(program initializes shared memory object and array)
I have a two dimensional array , who's parameters are decided by the user . Hence i cannot initialize it . Now i want to take input for the first the row and then check some condition and then move on and take input for the next row.
suppose I want to find the value of e ,e^x or sin(x) or any such function in general ,through their infinite series (maclaurin or taylor) how many iteration should I have to make to get the result correct uptu 'n' decimal places?
class Secure { private: int seconds; bool isRUNNING; public: Secure(int seconds) {
[Code] .....
ERROR:
error C2276: '&' : illegal operation on bound member function expression
I read that due to explicit casting, threads cannot be created within a class. I'm trying to thread a scanning system to relieve stress on my main program/module, rather than having the scanner stunt their performance.
Very new to programming, and I know that there must be another way on inputting a string into each array cells not by just inputting it one by one, but as a whole. My code at the meantime is: [URL]
