I have two possible questions; can you use a ternary operator to initialize objects with overloaded constructors like
class thing
{
int x;
int y;
[Code].....
I can get around it if I need to but I'd like to learn more about the ternary operator if I can, since I couldn't find anything online that addressed this particular issue, at least in a way I could detect.
1.WAP in C++ to enter marks in 3 subject and calculate percentage and grade.cond given below (Using Ternary operator)
Per Grade
90-100 A
80-90 B
70-80 C
0-70 D
2. WAP to enter 3 no.s in and print them in ascending and descending order .(Using Ternary operator)
I have to implement the following class:
class MyString {
private:
char *str; // Pointer to the char array that holds the string
int strLength; // Variable to store the length of the string
public:
// Default constructor to initialize the string to empty string
MyString();
[Code] .....
How can I define overloaded constructor at line 12.
#include<iostream>
using namespace std;
class Cents {
public:
int m_nCents;
Cents(int nCents=0):m_nCents(nCents){
cout<<"Calling normal constructor with value:"; m_nCents = nCents;
cout<<m_nCents<<endl;
[code].....
Question is :Why is the overloaded copy constructor that I have written not getting called here?Internally default copy constructor is getting called.Thats why we get value of obj2.m_nCents as 37.
What is another way I could convert string to int in this overloaded operator? This way gives me an error.
Code:
istream &operator>>(istream& in, MasterData& d) {
string value;
getline(in, d.playerId, ',');
getline(in, d.firstName, ',');
getline(in, d.lastName, ',');
[Code] .....
why can't << operator be overloaded as a member function is it because that is the way c++ is written and you just can't or is there another reason because I'm confused.
View 2 Replies View RelatedI don't exactly know how to test my ==friend function in my main.
Here is my .h file:
#include<iostream>
using namespace std;
class Car{
public:
Car();
Car(int yer, string mke);
[Code] ....
I'm using some overloaded operators (addition, subtraction and variants of) in part of my final major project and, when coming to test it, I've noted that they appear to be killing my pointers eventually.
I say pointers, it's always the same one. But I have isolated it to being the operators. The only two I'm really using are += and -=, though I've defined the others for consistency.
Either A ) what it is I've done wrong (if I have) or B ) why I would see this behaviour. Or, you know, if there's something glaringly obviously wrong with the code that I'm glossing over.
Code is as follows
#pragma once
#include "stdafx.h"
namespace gunpei {
/**
A paired register in the form of r1r2
Enables using two separate arrays for register processing
provides logic for assembling pair and breaking back into individual registers
*/
class GBPairedRegister {
[code]....
I'm trying to assign a value to a member of a struct that I called via an overloaded [] operator. I have the following code for the struct:
typedef struct {
float r, g, b, a;
float operator [](int pos) {
switch (pos) {
[Code] ....
And what I wish to do is
MyStruct a;
a[0] = 0.5;
Is it possible with a struct? How to express this to search engines so I haven't been able to find anything about it. If this is not possible with a struct, is there a way to define something that can do all the following things:
SomeStruct test = {0.5, 0.5, 0.5, 1};
test.g = 1.0;
test[0] = 0.0; // test[0] would be equivalent to calling test.r
float somevalue = test[3]; // test[3] would be equivalent to calling test.a
I hope I've been sufficiently clear.
I designed a class template to create unique arrays. I was able to successfully input data to and output data from my array objects, irrespective of the datatype. However, I can't for the life of me fathom why my overloaded assignment operator worked perfectly well only for integer datatype and not for double/string datatypes.
Here is the class definition:
template <class dataType>
class myArray {
public:
void setArrayData();
[code]....
And here is the definition of the overloaded assignment operator:
template<class dataType>
const myArray<dataType>& myArray<dataType>::operator=(const myArray<dataType>& rightArray) {
int i;
if(this != &rightArray) {
delete [] arrayPtr;
[Code] ....
And here is my main function that tests the operations on objects of the class:
int main(){
//object declarations
myArray<double> list(5); //a single-parameter object declaration of class myArray
myArray<double> myList(2,13); //a two-parameter object declaration of class myArray
[code]....
The problem I'm having starts from where the assignment operator is being tested: for double and string datatypes, the upper input/output section works fine, but the assignment section freezes the display until the program execution is manually terminated!
I have a class matrixType that has some overloaded operators (+, -, *, and <<). With a view to having clearly-delineated, perfectly-formatted, four-sided matrices, as shown below:
A = 1 2 3
4 5 6
7 8 9
or
A + B = 1 2 3
4 5 6
7 8 9
and NOT this jagged ones shown below:
A = 1 2 3
4 5 6
7 8 9
or
A + B = 1 2 3
4 5 6
7 8 9
,
I want a scheme in which the string literals (A, A+B, etc.) could be passed as parameters to the overloaded stream insertion (<<) operator function so that I could use the string’s length to determine how much offset from the display screen’s left to apply to each matrix’s row (by using the setw() function). However, I do know that the << operator is a binary operator, meaning the function cannot take more than two parameters: that is what compounds my problem!
I am working on an assignment in which i have to perform th following task
myClass itsObject1,itsObject2;
itsObject2=5000+itsObject1;
I have defined overloaded operator as follows in the header file but in the cpp file of the class it gives error.
friend vli &vli::operator + (int &a,vli &obj);
How to define it in cpp file of my class?
How do i write main test program to test the copy constructor and assignment operator in this program...how do i know if its working as its suppose to?i just want to know about copy and assignment operator..i have figured out the test program for other things..Here my program :
ListType.h
#ifndef LISTTYPE_H
#define LISTTYPE_H
#include<iostream>
class ListType{
public:
ListType(size_t=10);
ListType(const ListType&);
[Code] ......
I've been working on some project and I got to wondering when you know you need to use a copy constructor and an assignment operator. Is there a rule of thumb? I know there is the Rule of Three, but is there something that tells you when you need those three?
View 4 Replies View RelatedI'm working on a project and I'm not quite sure how to implement the Copy constructor and Overloaded assignment operator.
This is what the instructions say if that matters at all: Since you have dynamic variables in your class, you should make sure that the big three are implements. You already have the destructor, but you will need to add a copy constructor and the overloaded assignment operator. This is simpler than it sounds, but it requires some thinking. You need to make sure that both the copy constructor and the assignment operator create new containers.
Here is my header file:
#ifndef CANDIDATELIST_H
#define CANDIDATELIST_H
#include "CandidateType.h"
#include <iostream>
[Code].....
I know I don't have much in these functions but I'm not sure how to apply them or if I'm even headed in the right direction.
Go to this link : [URL] .....
Actually I am not getting one thing in this code that why they only provide the declaration of Copy constructor and Assignment operator...??
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{
[code]....
VS 2012 / Windows 7 64 bit
class
class myclass {
public:
myclass(){/*stuff here*/}
myclass(int* p) {MyPointer = p; myclass()}
[Code] ....
it works until the myclass(int* p) calls myclass()
then the MyPointer will become CCCCCCCC (NULL value)!
is there a way to stop the second constructor from resetting the pointer value to null?
I'm doing a refresher for C++ and have gotten to operator overloading. I'm trying to perform an operator overload with the insertion (<<) operator, but I have encountered a problem.
Here's my class [In a header file "Shinigami.h"]
#include<string>
namespace K{
class Quincy;
class Shinigami{
friend std::ostream& operator<<(std::ostream&, const Shinigami&);
[Code] .....
If the operator function is a friend of the 'Shinigami' class, why doesn't it recognize any of it's private members? I need it to be in this file because I'm doing a bit of association with the 'Quincy' class.
I thought it was the namespace, but I included that.
I am currently having trouble to have getline to read line from the file. Error is: "no instance of overloaded function "getline" matches the argument list"
code is as follows:
std::ifstream config("config.txt");
string process[4];
int linecount = 1;
if (config.is_open)
{
while (config.peek() !=EOF)
{
getline(config, process);
linecount++;
}
}
I am trying to use constructor within constructor in the same class. Is that possible. I have tried something and it shows me a error message:
error: type "mainClass" is not a direct base of "glavna"
This is the program I tried:
Code:
class mainClass {
private:
int x,y;
Code] ......
What I'm trying to do is create a class for constructing an 'op tree' for parsing infix notation.
I started with a base class that uses a map of lambdas to actually calculate the operations (since they are mostly 1 line functions) of passed in integer or float values.
This base class just uses a templated T type as the lvalue and rvalue. I realized though that if I overload the math operators, +, -, etc.. I could also use the class itself as a type for the lvalue and rvalue. This lead me to think I could easily create the op tree by using Operation class members themselves as operands, which I think makes sense but I'm having some trouble expressing the code.
Heres what I have thus far
Code:
#include <map>
#include <string>
#include <algorithm>
#include <iostream>
namespace Calc {
[Code] .....
Example, if you look at the main() function I create normal operations easily with integer values. I then try to create a "tree" operation that includes 2 sub-operations as it's rvalue and lvalue, that is where I'm having some conceptual problems as far as implementing the code to do that.
I'm having an issue with output, luckily everything else works!! I'm working with Mixed Numbers and operations on them. So, here's the code I'm testing with:
int main() {
Mixed m1(5), m2(1,1,1), m5(2,2,3);
cout << "m1+m2= " << m1+m2 << endl;
cout << "m1 + 10=" << m1+10 << endl;
cout << "m1 - 10=" << m1-10 << endl;
return 0;
}
And here is the output for that code:
File name: fract.h
#ifndef fract_H
#define fract_H
#include <iostream>
using namespace std;
const int DEFAULT_VAL = 0;
[Code] ....
I keep getting this error in my code. I believe it is because to use pow(x,y) both x and y have to be double, but how do i put that into my formula under calculations?
#include <iostream>
#include <cmath>
#include <iomanip>
#include <string>
#include <fstream>
using namespace std;
int main() {
// Declaration section: Declaring all variables.
[Code] ....
I've got the following code with output. I can't figure out myself why it's what printed out there. I believe, it has something to deal with overloading/overriding/virtual functions implementations in C++:
class Base{
public: virtual void f(int);
virtual void f(double);
}
[Code].....
Thus here're my conclusions:
1) in line
d.f(1.0);
for some reason compiler preferred casting double->int of the argument and then call to 'Derived::f(int)'.
2)in line
pb->f(1.0);
for some reason compiler preferred call to 'Base::f(double);'. 'Base' is static type of pb, but the dynamic type is 'Derived'.
I believe the answer has to deal with the fact whether virtual table contains in addition to functions' names also the types of arguments they accept. AFAIK, vTable doesn't include such info.
I believe I have the syntax correct but I'm having difficulty calling my overloaded == operator in main (last snip-it of code). Below are several files explaining the code.
Commission.h here is where the friend bool operator == exists and I believe I have it initialized correctly.
#ifndef COMMISSION_H_INCLUDED
#define COMMISSION_H_INCLUDED
using namespace std;
class Commission {
public:
Commission();
Commission(int, double, double, double );
~Commission();
[Code] .....