Here is a sample of my question
class Base{
public:
int getNum();
private:
int numToGet;
}
class Derived: public Base {
public:
friend ostream& operator<<(ostream& output, const Derived &B);
[Code]...
Say I have 3 classes:
class Player {
public:
virtual func1();
[code]....
Say in my main class, I have a function fight(Player p1, Player p2) and I would like to do something like this in the fight function, given that p1 is the human and p2 is the computer:
//function fight()
fight(Player p1, Player p2) {
p1.func2();
}
//using function fight()
fight(human, computer);
When I compile the program, I got this: error: ‘class Player’ has no member named 'func2()' What can I do to allow p1 to call func2 inside fight()? I'm not allowed to use pointers as the parameter for fight() and have to use the signature fight(Player p1, Player p2).
I'm trying to call a function on a derived class that's in a vector of it's base class. I've made the code really simple for illustration purposes:
class Sprite {
virtual void update();
}
class Enemy : public Sprite {
virtual void update();
[Code] ....
I want to be able to just call update() on the items in the vector and the derived class update() functions be called. Currently, it always calls the Sprite update, which makes sense, but it's not what I want. Is there a way to call the derived update function without knowing the type of the derived class?
How can a member function in my derived class call the same function from its base class?
View 1 Replies View RelatedI'm having some difficulties in understanding the topic which I stated above.
View 5 Replies View RelatedSo I have a base class, lets call it base. In base I have a virtual function called update(), update just couts "base" then I have a class derived from base called derived;
it has a function called update(), update just couts "derived" then I create a vector called Vec it's initialised like this:
std::vector<base> Vec;
then I add an element into it like this
Derived DerElement;
Vec.push_back(DerElement);
then when I type:
for (int i=0; i<Vec.size(); i++) {
Vec.at(i).Update();
}
It outputs:
Derived DerElement2;
DerElement2.Update();
and it outputs this:
#include <iostream>
#include <vector>
class Base {
public:
virtual void Update() {
[Code] .....
and this is it's output:
Base
Derived
Press any key to continue . . .
I just wondering if a base class can call the overridden function from a Derived class?
Here's an example:
//Base Class H
class BaseClass {
public:
BaseClass();
virtual ~BaseClass();
virtual void functionA();
[Code] ....
So basically, when I am creating a new object of Derived class, it will initialize BaseClass and the BaseClass will call functionA but I want it to call the function overridden by Derived class.
I know that if I call newObj->functionA it will call the overridden function. Right now I want the base class to call the overridden function "this->functionA(); in BaseClass" during its initialization. Is it possible to do that?
Basically, I have a base class called MainShop and it has 3 derived classes which are SwordShop, SpellBookShop and BowShop. I want the base class to be able to call a function from one of the derived classes but no matter what i do, it doesn't seem to work!
Here is my code:
#include "MainShop.h"
//BaseClass cpp
void MainShop::EnterShop(Hero& hero)
[Code]....
I have two other derived classes, but its basically the same concept. I have a function in one of the derived classes and i would like to call it from the base class. This is one my derived classes:
//SwordShop derived cpp
#include "SwordShop.h"
void SwordShop::soldierShop(Hero& hero)
{
/* some code here*/
}
I searched the web for error: C3867... and the discussions where murky or obscure.
My code excerpt is:
#pragma once
#include <windows.h>
#include <stdlib.h>
#include <process.h>
void PutUpfrmIO(void *);
namespace WordParsor {
[Code] .....
I get the generic message:
error C3867: 'WordParsor::Form1::PutUpfrmIO': function call missing argument list; use '&WordParsor::Form1::PutUpfrmIO' to create a pointer to memberc:userskingc++wordparsorwordparsorForm1.h... and the suggestion fix generate another error.
One person suggested the gcroot<> object wrapper... but I do not know how to modify/declair the function or its argument type.
The function is supposed to return value from the file in my main, but I am getting empty value. I am trying to get better with pointer. Right now just teaching myself.
right now the only way for this code to show value is when in put the putchar(*ps) inside my readfile function. I would like to readfile to return value and print in the main function.
Code:
#include <stdio.h>
char *readfile(char filename[]);
int main(int argc, char *argv[] ) {
[Code].....
Is this possible?
int myfunc( int a, int b, char * c )
char a = "(int)myfunc()";
char b = "(int,int,char*)"
call(a, b, ...) // Function name and return type, params
I want to do function what registers forward what will get callback if the time is right. Basically then i dont need to edit and add extra functions into source files. I just have to include header and use register forward function. If there is anything close to this it would be perfect!
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] .....
Im trying to create a map container with the key being an ID number and the value being a pointer to a class object. Currently Im creating objects and storing their address in the container. I am getting a runtime error when calling the virtual method with this pointer. I believe that the problem is being called because they aren't being called pointer/reference. let me know if you need more.
if(command == 'F'){
inputDataFile>>name>>mNumber>>email>>department>>tenure;
faculty newFaculty(name,mNumber,email,department,tenure);
person* facultyAdd = &newFaculty;
cout<<"Note: Adding "<<mNumber<<"..."<<endl<<"Adding ";
people.insert(pair<string,person*>(mNumber,facultyAdd));
[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 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 have a class Base (abstract, with pure virtual) and Derived (which inherit Base). I use this:
Base* A = new Derived();
But I can do this:
Derived A;
How make Derived dependent of Base in one file?
I would like to access (use) a (virtual) method declared in a base class via a pointer to an object belonging to a derived class, which overrides the base method. Is it possible? Up to now I have not been successful. I am including a program with a more detailed description.
// declare a base class T0 with virtual function P, and a derived
// class T1 which overrides P; declare two ptrs, to T0 and T1,
// and generate corresponding objects; calling P via the two
// ptrs gives expected result; however I would like to take
// ptr to T1 object & execute the base function (declared
// in T0); is it possible? I tried all possible casts but nothing
// works; no matter how I cast the pt1 ptr, I always end up executing
// the overriding function (declared in T1)
// actual output (debian 7, gcc 4.7.2-5):
[code]....
How would I call a string that sits within a switch loop in the main function, into a separate function?
Like this:
void statistics() {
cout << "Here are the statistics for your entry: " << endl;
cout << "
The size of your entry is " << s.length() << " characters." << endl;
}
I am calling string s from this:
switch (toupper(myChoice)) {
case 'A': cin.ignore();
cout <<"
Please enter your text: ";
getline(cin, s);
[Code] ....
I have two functions bool check_key(string cKey, string eKey) and bool check_digit(char digit1, char digit2), and I have declared both of them globally (is this the right terminology?) right after the "using namespace std;" and right before the "int main(){".
In the first one, I called the second one . But it is giving me the error: "no match for call to `(std::string) (int&)' ".
Code:
bool check_key(string cKey, string eKey) {
if(cKey!="" && eKey=="") return false;
if(cKey=="" && eKey=="") return true;
if(cKey=="" && eKey!="") return true;
if(cKey.length()!= eKey.length()) return false;
bool flag=true;
[Code] ....
I need to return taxes paid and net pay by pass referencing a gross pay overloaded function. Are the values returned from calling the overloaded function file stream objects? Can they be passed simply through a pass-by-reference function?
//Read Data from File, gather info and calculate pay, output data to file
while(counter < x) {
inFile >> last_name >> first_name >> hours_worked >> hourly_pay;
outFile << first_name << " " << last_name << " ";
outFile << calculate_gross_pay(hours_worked,hourly_pay);
counter++;
outFile<<endl;
[code].....
#include<iostream>
using namespace std;
#include<string>
main() {
cout<< "donner votre nom:";endl;
string nom("sans nom");
cin>> nom;endl;
cout<< "votre nom est:"<<nom; endl;
return 0;
}
when i try to build this program, i get this masseges:
in function 'int main()':
statement cannot resolve address of overloaded function
this a picture of the errors:
how to create a base class that is derived (inherited) by three other classes?
View 12 Replies View RelatedIs there a way to copy a derived class object thru a pointer to base?
For example:
class Base { public: Base( int x ) : x( x ) {}
private: int x; };
class Derived1 : public Base { public: Derived( int z, float f ) : Base( z ), f( f ) {}
private: float f;};
class Derived2 : public Base { public: Derived( int z, string f ) : Base( z ), f( f ) {}
[Code] ....
The question is whether *B[0] would be a Derived1 object and *B[1] a Derived2 object?If not, how could I copy a derived class thru a pointer to the base class?
I can't seem to figure out whats causing this error: statement cannot resolve address of overloaded function . Error is before line 14 in bubblesortrand function. Thnx in advance.
void bubblesort(int num[], int a_size)
{
int i, j, temp;
for(i = (a_size - 1); i >= 0; i--)
[Code].....
The question involves me writing a program using a overloaded function to calculate the Weekly rate of employees but they get paid hourly and weekly. I get this error but do not know why,
#include <iostream>
using namespace std;
int calcWeeklyPay(int paidWeekly, int annualSalaryWeekly)
//Returns the Weekly salary of weekly paid Employees
int calcWeeklyPay(int paidHourly, int annualSalaryHourly)
//Returns the Weekly salary of Hourly paid Employees
[Code]...