I get the error at the line "ptr1 = new node;" I tried putting a default constructor for my node struct and that fixed the problem but a new problem arises. It states that i have a linker error after i compile it with a default constructor.
First I wrote a Binary-tree class to draw a binary tree on the window. The nodes were small circles. Then I become wanted to change the shape of the nodes from circles to triangles by another class, Binary-tree-derived which is derived from Binary-tree class. I wrote the below code to do the job but I get two errors about constructors. First, code:
/* The binary-tree class, one of the topics that has been said in Programming Principles and Practice using C++ book by Biarne Stroustrup. This code is written by R Abbasi (s.rabbasi@yahoo.com) */ #include <Simple_window.h>
[Code].....
Errors are:
Error12error C2512: 'Binary_tree' : no appropriate default constructor availablec:userscsdocumentsvisual studio 2012projects est_1 est_1 est_1.cpp91
13IntelliSense: no default constructor exists for class "Binary_tree"c:UsersCSDocumentsVisual Studio 2012Projects est_1 est_1 est_1.cpp91
How do you write a default constructor?I need to use a default constructor that will initialize the data members: - salesPerson to “Unknown” - noOfWeek to 13 - amount to point to an array of thirteen 0.00s.
This is my weeklysales class
class WeeklySales { char* salesPerson; double* amount; // Pointer to an array int noOfWeek; // Size of the array };
A compiler auto created default constructor is called a synthesized default constructor. It will initialize the built-in members to 0 or not depends on where the class object is defined? if I define a class
class point{ public: double x, y; };
if I define point point1; in global scope then point1.x and point1.y will be initialized to 0, if I define point point2; in a local scope, then its x and y won't be initialized? If it is like this, then I believe if there are built-in type members in a class, then the synthesized default constructor is almost useless!
To my best understanding, the compiler will provide me with a deafult constructor only if there are no any user defined constructors, at all. Now consider the following code:
Code: class MyClass { private: int m_data; public: MyClass(int init):m_data(init){cout<<"Ctr called"<<endl;}
[Code] ....
How is it that suddenly, there is a default constructor?
trying to practice the object-oriented part of it by converting my java programs into c++. I believe I understand the concepts of a header file and declaring the functions in the .cpp files. I keep getting this "Undefined reference to NamedStorm::NamedStorm()" error.
NamedStorm.h #ifndef NAMEDSTORM_H #define NAMEDSTORM_H #include <string> #include <iostream> // NEVER use using namespce in header, use std instead. using std::string;
Im trying to create two box in this program using the default constructor. When i call to try and display the info, it says that x, y, and z are not declared in this scope. i wanted to have the user cin the length, height, and width using the void setBox function.
#include<iostream> #include<string> #include<cstdlib> using namespace std; class Box{ public:
class Date Date(int=1, int=1, int=1990); class Person Person(string="", string="", Date=NULL); class RealEstateAgent:Public Person RealEstateAgent(string="",string="",Date=NULL,Date=NULL,int=NULL, double=0.0); }
[code]....
how can I assign default values with Customer object and RealEstateAgent?
I am creating a Matrix class, and one of the constructors parses a string into a matrix. However, printing the result of the constructor (this->Print()) prints what I expect, and an <object_just_created>.Print() call returns bogus data. How is this even possible?
Snippets below:
Matrix::Matrix(const string &str) { // Parse a new matrix from the given string Matrix r = Matrix::Parse(str); nRows= r.nRows; nCols= r.nCols;
[Code] ....
in the driver program, here are the two successive calls
Matrix mm6("[1 2 3.8 4 5; 6 7 8 9 10; 20.4 68.2 1341.2 -15135 -80.9999]"); mm6.Print(); // mm6.Print() calls bogus data, -2.65698e+303 at each location. The matrix's // underlying array is valid, because printing the addresses yields a block // of memory 8 bits apart for each location
I am confused for first call to push_back copy constructor is called for second call I am expecting it to move class instance to new memory location there by trigering move and then inserting second class instance expected call:
Copy constructor Move constructor Copy constructor but its calling Copy constructor Copy constructor Move constructor
Im trying to Get the ID column (which is int type) from items selected from a checkboxlist. The checkboxist is populated by the ID column (UserID). I want to get all the UserID values from the options selected in the checkboxlist and populate a table in sql server with the selected UserID's once a button is clicked.
Heres what I have at the moment...
foreach (ListItem oItem in UserChkList.Items) { if (oItem.Selected) { //Populate //--------- UserProject = new ob_UserProject();
[code]....
This is the line thats not functioning as i want it too. Returns an error 'Cannot implicitly convert type 'string' to 'int
Is there any way to set a "lock" on certain couts from system ("cls"). You can this with const to "lock" a variable to a certain value so I am wondering if that is true for couts from system ("cls"). This would make my program much simpler to write.
I am working on C# Project [Windows Form Application], to update treeview nodes from excelsheet [xls] Cell [row i, Column 3] Values, while on selecting treenode, it should update corresponding Column 4 Value [row i, Column 4]. For me, Treenode are populated successfully, but on selecting the treenode, it always display first Element of treenode [Not selected one].
Populated Treenode from Excel as: [ Update Child Nodes from Column 3 elements [Column 2 Contain Parent node name and Column 3 have Child Node name], if Column 2 Value is same as Parent node name [My Module], update the child nodeunder same Parent node.]
for (int i = 0; i < worksheet.UsedRange.Rows.Count; i++) { string mynode = ((Excel.Range)worksheet.Cells[i + 1, 3]).Value2.ToString(); string mynode2 = ((Excel.Range)worksheet.Cells[i + 1, 2]).Value2.ToString();
[Code] ....
On selecting the Child Node, it always give 1st Parent node. Instead of Selected Node.
for (int i = 0; i < worksheet.UsedRange.Rows.Count - 2; i++) { string mynodetext = ((Excel.Range)worksheet.Cells[i + 2, 3]).Value2.ToString(); string mynodetext1 = ((Excel.Range)worksheet.Cells[i + 2, 4]).Value2.ToString(); if (treeView1.SelectedNode.FirstNode.Text == mynodetext) { this.richTextBox1.SelectedText += Environment.NewLine + mynodetext1 + Environment.NewLine; } }
Been away from c++ for a few months now (apart from answering a few questions on this site). I was trying to see if I could do a simple program using just my memory that involved unique_ptr's, but getting an error:
"attempting to reference a deleted function". I thought that by getting a reference to my pointer would not invoke a copy constructor but i'm clearly wrong.
I'm having a hard time figuring how to get my imagelist index 3 icon to display in the nodes "N1" and "V Speeds" below? So, as you can see in the attachment, the closed folder icon is currently shown which is index 0 in the imagelist. But I want index icon 2 to show in these two nodes.
Say I have an object and 10 pointers to it in several other objects of varying class types. if the object gets deleted, those pointers have to be set to null. normally I would interconnect the object's class with the classes which have pointers to it so that it can notify them it is being deleted, and they can set their pointers to null. but this also has the burden that the classes must also notify the object when THEY are deleted since the object will need a pointer to them as well. That way the object doesn't call dereference a dangling pointer when it destructs and attempts to notify the others.
Auto pointers and shared pointers are not what I'm looking for - auto pointers delete their object when they destruct, and shared pointers do the same when no more shared pointers are pointing to it. What I'm looking for is a slick method for setting all pointers to an object to null when the object destructs.
I have a small questions in the behavior of Structure, I have declare a structure with 10 components. Some of the components in the structure has already their value but when I use
The structure components in a function DLL function those value I set previously has been deleted or empty. I don't know what is the problem...
1. I want to make a file in the program directory that can't be deleted by user out of the program make that file.for example if I make a file named "123.xyz" by the program named "text.exe" and then exit test.exe ,if I tried to delete the file 123.xyz I faced the error and I could not do it but by the test.exe program that make that file.
2. I heard about a function called "Parbegin()".any way i want to know is there any possible way to run two or more functions of a file.c together,like the parbegin function did an do in OS?
i am writing this bank accounts program using structures. i haven't implemented the function before that i want to check if the data is being read and printed. When i build and run the program in visual studio it gives me the following error. "No constructor could take the source type, or constructor overload resolution was ambiguous". Now whats wrong in this program?
/* Bank Accounts Program */ #include <iostream> #include <string> #include <fstream> #include <cstdlib>//needed to use system() function using namespace std; const int MAX_NUM = 50; struct Name{
