I'd like to start out by adding an array to a C++ class. I'd like to be able to reference the array using a class object that I create, for example:
Class is Stone.
Stone Bob is an instance of "stone" that I name "Bob".
"Bob.array[1] = "granite";" tells the compiler that the second element in the array (with the first being the zeroth element) is a string containing "granite".
I'll eventually want to extend this to an n x m matrix within the "stone" class that can be referenced as: Bob.matrix[1][3]="lignite";
I tried to make this work using a text again and again last night to no avail. My code is below.
NOTE: Since I am dynamically allocating memory space, I'd like to avoid memory leaks when using this class with dynamically allocated arrays and matrices. Not sure how to do this. Also need some insight into "destructor", and why my simple version reduced to a comment below doesn't seem to please the compiler.
CODE FOLLOWS:
Code:
// AINOW.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <iostream>
#include <string>
using std:: string;
using std:: cout;
using std:: endl;
using std:: cin;
I am trying to add matrices a and b. I am getting an error in the "add" function, probably because I have m[i] in it, and m is not an array. What is the correct way of writing the "add" member function here?
Also, although the "read" and "write" member functions of the class are working just fine, do you think there is a better way of writing them?
Code: #include <iostream> #include <cmath> #include <iomanip> using namespace std; const int rows=3; const int columns=3;
This is my code without malloc. I need to change the array size so there is no max size for each matrix. I must dynamically allocate space for all arrays used. So I need to use malloc to create my arrays. So I cant use int A[rows][cols].
Code:
/* This program asks the user for 2 matrices called A and B, as integers, and displays their sum, C. The max dimension of each matrix is 100. */ #include<stdio.h> // Construct function void construct() { int m, n, i, j;// Variables int first[100][100], second[100][100], sum[100][100];// Matrices variables
[Code]...
Im having a hard time understanding/using malloc. Should first, second, and sum be single pointers or double? How do I scan the matrix correctly? And how do I add them properly? Do I have to change my for loops?
Code:
/* This program asks the user for 2 matrices called A and B, as integers, and displays their sum, C. The max dimension of each matrix is 100. */ #include <stdio.h> #include <stdlib.h> // Construct function void construct()
I need to input values for two arrays and then add the two with all of it being print visible. I have this so far but can not figure out how to add the two arrays.
#include <iostream> using namespace std; int main () { { int const ROWS = 3; int const COLUMNS = 3; int square[ROWS][COLUMNS];
You will have two file streams: an input file stream for the file to be normalized and an output file stream that contains the normalized file. You should issue an error message and exit the program if either file cannot be opened. Your program should prompt the user for the filename of the file to be normalized (the input file). The output filename should be the input filename with ".normal" added to it. For example, if the input file is "data.txt", the output file name will be "data.txt.normal".
Be careful to not leave an extra blank line at the end of your output file.
My question here is how do I rename the file that the user entered to have a ".normal" at the end of it? I was thinking along the lines of having to string names and changing the second string's name and use that as the output file. any examples cause I didn't exactly get that to work.
I need to add thevArr[I] and vArr1[I] and store in vArr2[I] but I cant figure out how to drop the value or replace with a 0 if vArr is bigger than vArr1. IE: 1st number: 123 2nd number: 4567
Ill get something like this: 1 2 3 4 5 6 7 5 7 9 -827349
I am currently working on a program that uses a class to store integer arrays. I have most of the code done, but I am having trouble on the main.cpp part of my program. The program should display this:
I have a matrix that contains zero and nonzero elements. I want to do a function that return 3 arrays.
The first one is for nonzero elements the second array contains the corresponding row numbers of each nonzero element the third array contains the corresponding column numbers of each nonzero element.
I'm writing a program with two classes, one that contains a card's rank and suit and the other contains pile of these cards. I'm having trouble when it comes to adding a pile to another pile...here's what I have so far:
class Card //Card class declaration { private: int rank; //invoking rank char suit; //invoking suit public: void setCard(int r,char s); //determines card suit/rank
[Code] ....
I understand that I'm calling my pile arrays incorrectly, but I'm not sure why.
I have been working on an assignment where I have to add three objects of a class Matrix. The class should have the flexibility to add more than two oprands without changing any operand on Left hand side of the '=' operator.
I have implemented matrix class using vectors. code is
template <class T> class CBSMatrix : public CBSVector< CBSVector<T> > CBSMatrix(long r,long c, T t) { setsize(r, c); init(t);
[Code] .....
Although i have implemented the cols() but things in it are confusing me specially this line "if(size()) return at(0).size();" and "CBSVector<T> v(cols());" this line in add row function is also troubling me. in main i have done some thing lyk CBSMatrix <int> mat(5,5,0); now how to put values in this matrix. How to put values in this template based and vector based wired matrix because first row is created in this and then cols are added to that row.
I'm working on a matrix class and I've hit a few snags. Here's what I've got so far:
Matrix.h
#include <iostream> #include <conio.h> using namespace std; class Matrix { private: int matrix[50][50];
[Code] ....
Where I have questions is in implementing the addition and subtraction bits into the class itself. I understand that I'm going to have to do a copy operation (this from reading in C++ Primer Plus 5th Edition). Right now I'm just after adding/subtracting as the rest will be variations on the same theme.
So, here it goes:
As I understand the problem, I need to pass my two matrices as arguments to an addition function. This is going to involve having to copy the values of the two existing matrices into temporary matrices within the addition function, then I'll add them, and store them in a new matrix which will be my return value. So...something like this:
int Matrix::matrixAdd(int R, int C, const Matrix & matrix1, const Matrix & matrix2) { int sum; Matrix matrix; for (int i = 0; i < R; i++)
[Code] ....
I do end up with errors there...C2240, and C2662. Again, I'm new to working through this, but that's what I've got. My idea is that I'm passing the maximum size of the array as defined by the user, in this case a 2x2 array, it'll cycle through and add up to that imposed limit...I went 2x2 because it's small enough that testing doesn't drive me up a wall.
I had written a "DLL" in VB.NET a year or two ago to read and set MP3 tags. I want to write this exact same library in C++ so I can convert it in my droid project, and to get a hands on introduction to C++. So far this attempt has been a total mind melt!
I am finally wrapping my head around .cpp and .h files so there is light at the end of this tunnel. Here is my problem now:
I wrote the VB project with properties for each tag in the MP3 file, then I could get and set them - easy stuff.
When I try this in C++ I get compile error: a property can only appear within the definition of a managed type. I can usually stumble through Google searches and figure out this type of stuff on my own, but this one is stumping me -- I think I am missing some fundamental stuff here.
My code:
// MP3Tags.h #pragma once; #include <string> using namespace std; using namespace System::IO;
I have an inventory array in a class called inventory. This class is in a different program. How do I access and add to this array for my main program?
I'm attempting to make a matrix class, and so far I've made a member that can make a vector of vectors, but I'm not sure how to go about resizing the vectors if need be.
EX: resizeArray(3,3) should return a 3x3 vector.
Also, for some reason when I call my default member, matrix(), I get an error that says.. "Request for member numrows in myMatrix, which is of type matrix<int>[][]"
#include <iostream> #include <vector> using namespace std;
void replace(string oldstring, string newstring) { int stroldstringpos=b.find(oldstring); b.replace(stroldstringpos,newstring.length(),newstring); }
i have 1 error in these function that i'm confused. imagine the newstring size is more big than the oldstring, how can change the string, but only change the oldstring and add what left? see these:
I am IT student and had a C++/C (oral + paper) exam today. One of the tasks was to write a 2D-Matrix (as the question said) class with following restrictions:
- No <string> header is allowed - Only Dtor needs to be implemented - No templates - Following should be possible:
Code: std::cout << mat1 + mat2 + "some randome string"; mat1 += mat2; So i did the following: In Matrix.h i wrote: Code: Class Matrix{ int rows, cols; char *arr[][];
[Code] .....
Now..this destructor made me loose some points since the Prof. said that it is not correct. The corrected version was:
Now, i agree on that error i made, but it is only in case we use the "new" keyword to reserve place dynamically for each string(for each char*). So this raised the question in my head about:
Since the following is allowed in C++
Code: char* str1 = "hello"; char* str2 = "you"; arr[1][3] = str1;//arr[1][3] was initialized to "_" without new keyword arr[6][0] = str2;//arr[6][0] was initialized to "_" without new keyword why would someone use the new keyword..
I mean like this:
Code: arr[1][3] = new char*[sizeof("sometext1")+1]; arr[1][3] = "sometext1"; arr[6][0] = new char*[sizeof("sometext2")+1]; arr[6][0] = "sometextw";
What is happening internally in C++ in both the cases(with and without new keyword)?
I realized a Matrix class to practice and I have a problem I can not solve! Here my problematic code:
Mtrx.h:
Code: template <class T> Mtrx::Mtrx(dim m, dim n, const bool random_constructed = false, const T min = static_cast<T>(0), const T max = static_cast<T> (10)) Mtrx.C
[Code] ...
And here the relative main section:
Code: Mtrx rand1 ( 5, 5, bool);// ok cout<<rand1<<endl;
Mtrx rand2 ( 7, 3, bool, -5, 20);// ok cout<<rand2<<endl;
Mtrx rand3 ( 7, 7, bool, 0., 15.);// compilation error: undefined reference to // "Mtrx::Mtrx<double>(unsigned long, unsigned, bool, double, double)" // collect2: error: ld returned 1 exit status
I am trying to add data from a file that would go into a class that would later go into a vector of a class. I'm not really sure how to do it exactly. Here is the code:
Champion_Info.h
#ifndef CHAMPION_INFO_H_INCLUDED #define CHAMPION_INFO_H_INCLUDED #include <vector> #include <string> using namespace std; class Champ_Info {
