i ran the following code in the latest version of code::blocks and it tells me that the objects cout and cin are not declared in this scope. what is the problem?
I used to use Turbo C++ 3.0 and i had no problem whatsoever with that compiler. But now i am trying to move to code::blocks but it is proving very very hard as all the standards have been changed.
I am a school student and thus, we had been told to practice on Turbo C++ 3.0 and now i am unable to unlearn it. Also, if i use printf in place of cout there is no error but i want to use cout as it is what i am comfortable working with.
#include<fstream>
#include<conio.h>
int main() {
using namespace std;
char name[20];
[Code] ....
Is there some document to which i can refer so as to get the latest C++ standards which is C++0x i believe?
// Creating and joining string objects #include <iostream> #include <string> using std::cin; using std::cout; using std::endl; using std::string; using std::getline; // List names and ages void listnames(string names[], string ages[], size_t count) {
[Code] ....
I may be wrong, but the problem seems to be in the function "listnames". Specifically, the output statement inside the while loop. I don't understand , how the ++ operator is behaving in this statement. The output produced does not match what's printed in the book. I usually just type all the examples, but with this one I also downloaded the source code from the book's website to make sure the error wasn't due to mistyping.
In this book, item 3 is about never treat arrays polymorphically. In the latter part of this item, the author talks about the result of deleting an array of derived class objects through a base class pointer is undefined. What does it mean? I have an example here,
Code: class B { public: B():_y(1){} virtual ~B() { cout<<"~B()"<<endl;
[Code] ....
This sample code does exactly what I want. So does the author mean the way I did is undefined?
#include <iostream> using namespace std; class superclass; class subclass1; class subclass2;
[Code] ....
As you can see I want to create a dynamically allocated storage of references to a parent class each of which can then point to a child class, how ever I do not know how to extract the child class out again from that array so i may access its variable b.
Let's say I have a Car object , and it contains inner Engine object.
Code: struct Car{ Engine mEngine; };
In order to initialize the engine object NOT by the default constructor (if it has any) , we use initialization semantics:
Code: Car::Car: mEngin(arg1,arg2,...) { other stuff here }
Now it gets tricky: Let's say a Car objects has 10 inner objects, each object has about 5 variables in it . Car is a base class for , e.g. , Toyota class. you don't want the Car class to have a constructor with 50 arguments. Can the inner objects of Car be initialized from the base class , e.g. Toyota?
Code: class Toyota: Car(...), mEngine(...), mGear(..) { ... };
The other options are: 1) like said , create a Car constructor which gets 50 arguments, then initialize Car as whole from Toyota - the code becomes less readable and less intuitive 2) Car constructor which get built-objects as arguments and initialize the inner objects with copy constructor . the code gets more readable but then you create many excess objects .
I keep running into this error, even though the first few times i built and ran something it worked perfectly, and since I'm new to CodeBlocks (or any IDE/Compiler for that matter) what to do.Any code i put in, it'll give me this error....
#include <iostream> double fact (int f); //declaration of factorial function double power(double x, int y); //declaration of power function double sin(int x); //declaration of sine function //double cos(int x); //declaration of cosine function //double tan(int x); //declaration of tangent function
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 need an array of class objects but am unsure of how one might accomplish this. I have so far...
//element class driver code Element Arsenic(lowCeiling, highCeiling); Element Cadmium(lowCeiling, highCeiling); Element Chromium(lowCeiling, highCeiling); Element Copper(lowCeiling, highCeiling); Element Lead(lowCeiling, highCeiling); Element Nickel(lowCeiling, highCeiling); Element Molybdenum(lowCeiling, highCeiling); Element Mercury(lowCeiling, highCeiling); Element Selenium(lowCeiling, highCeiling); Element Zinc(lowCeiling, highCeiling);
What I want to do is have an admin class which will hold all the employee objects, can add them, list and calculate salaries. I'm trying to make array of objects, not sure if it's right
here is the code
Code: #include <iostream> #include <string> using namespace std;
class Employee { public: Employee(string name, short type, int salary)
For a beginners C++ lab, I have a base class Employee and two derived classes HourlyEmployee and SalaryEmployee. In main, I have a vector defined as vector <Employee *> VEmp; It's then passed to a function to get the input, which works fine. But what I'm struggling with is another function with the header "printList(const vector <Employee *> & Ve)". It's supposed to loop through the vector and call the appropriate printPay function, which is a seperate print function inside each derived class. How do I loop through the vector and print it out? I was trying to do a for loop and something like "Ve[i].printPay();", but that doesn't work. So how would I do it?
Here's some snippets of the relevant code.
class Employee { .... virtual void printPay() = 0; }; class HourlyEmployee : public Employee {
I am working on a project that requires me to create objects from a abstract class that has 2 child classes (that need to be derived). Any examples on how to do this? I looked online and the examples were pretty vague. the main error that I am getting is when I make a temp object with & in front of it (such as Employee &genericEmp) it throws a must be initialized error.
Running into a snag in my program. I can't seem to figure out how to have an object of a class be able to look at all the other objects of its own class.
Reasoning being, I'm working on a game with multiple ships flying around in the same space. Each ship is a class. Each ship has an x and a y, and needs to compare the angle and distance of other ships' x and y coordinates to see if they're visible on the same screen.
How to tell an object to look at objects of its own class.
Here's some code:
common.h
#ifndef COMMON_H_INCLUDED #define COMMON_H_INCLUDED int dist(int x1, int y1, int x2, int y2); int get_info(int which);
[Code] ....
Basically, I just don't know how to properly write a function, call, or how to get the info I need, to the Player::get_closest() function so that it can see the other play objects.
So i'm actually using polyphormism for calculating the area of the cross and other shapes. so how do I actually make use of dynamically create an object this way?
do I create them in my Shape2DLink or in my individual child classes?
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;
I am new to C++ programming and i have a small assignment.
How to implement a thread safe class to manage a queue of objects. Accessing the front of the queue should be a blocking operation when the queue is empty.
I have written a selection sort algorithm to go sort an array of class objects by age in ascending order, the problem is that the output being given does not match what i think the code should do. when the program runs the 3 records are added to the array and when they are sorted should be outputed in ascending order, the problem is that with my code the last 2 are sorted properly but the first element does not seem to move, it remains the same as the original unsorted value.
My code for the selection sort function and the display method are below:
void selectionSort() { int i, minIndex, minValue; for (i = 0; i < (arrlength - 1); i++) { minIndex = i ;
I have a linear search algorithm set up to search through an array of class objects it works but the output does not match, when i search for a particluar name in the array the 1st and third values int the array are found but the second value is not found..
below is my code:
int linsearch(string val) { for (int j=0; j <= 3; j++) { if (player[j].getLastName()==val) return j ;
