C++ :: Stuck On Student Project / Classes And Objects
Aug 28, 2014
Working on a project for a c++ class and got a bit stuck.
What I am trying to do is include a class for calculating home square footage in a program I have written for my last project. When I do this, I get errors in codeblocks, on lines 74 and 87, "expected ; before 'box', and 'box' was not declared, respectively. Unsure what my snafu is... I had these two programs separate and both run without errors until I combine the two into one program.
Create an application to manipulate an array of student record objects. A student record will consist of a name (first, middle, and last), an ID number (9 numeric digits, cannot be more or less), an address (street, city, state, and 5 digit Zip code), and a phone number (3 digit area code and 7 digit number). The application will support an array of students. The user will be allowed to enter records from the keyboard, sort records by either name (last, first, middle) or by ID, save the records to a disk file (name supplied by user), and read the records from a disk file (name again supplied by user).
Create a fixed length string that must check that the length of the string is the required length. The fixed length class should be done as a template with the number of characters as the template argument. From this fixed length string, derive a class to hold digits of a fixed length.
Create component classes as necessary to use together to implement the student record class.
Use either the array template created in an earlier lab to handle the array or you may use the vector class from the STL to handle the array of student record objects.
The maximum number of students will be 25 (it may be less).
Here is the problem:"Write a program that converts a number entered in Roman numerals to a positive integer. Your program should consist of a class, say, romanType. An object of type romanType should do the following:
a. Store the number as a positive integer. b. Convert and store the number as a positive integer. c. Print the number as a Roman numeral or positive integer as requested by the user.
The integer values of the Roman numerals are:
M 1000 D 500 C 100 L 50 X 10 V 5 I 1
d. Test your program using the following Roman numerals: MCXIV, CCCLIX, MDCLXVI."I'm doing the best I can to understand the concept of the class. Here is what I have (which is not much thus far, and nowhere near correct I'm sure).
#include<iostream> #include<iomanip> using namespace std; class romanType { public: void getRoman();
I have startes making a game where there is 3 ships that cross the screen verticaly, and the point is to shoot them down. So far I have actually managed to do this. I have also managed to add gamescore to the ships. But here is my problem, I cant find a way to combine the score from all three ships in to one score. I have all three ships in different classes, is that wrong? When I try to combine the scores, ship score1 cant see the other scores.
Do I need to somehow have all the ships in one class. Or are there a way to read the scores from three classes, and adding them up in to one in a new class?
One of the errors I get is "the name 'score1' does not exist in the current context.
When are you creating fields/properties for specific classes and when you are not doing it but creating them inside just lets say straightaway inside some methods within that classes. I mean if i got class where inside i want to create instance of some other class and then pass this instance to another class - should i create a field for it within class i am doing this operation or not? I was always reading that you create field/properties when its belong to class itself. So if i want only to create some instance outside class i am working and pass it to other class and this is not exactly the part of this class shouldnt i create a field for it and just create it inside method?
I need to have an object of class A that doesn't have a default constructor in another class, B:
Code: class A; //This is in a separate header file class B { private:A a;};
The problem is that it won't compile without a default constructor. I'm not allowed to define a default constructor, and the A object in class B has to be private so I can't initialize A a in public.
I also can't change the prototype in the interface to something like
A(int a = 0, int b = 0);
since one of the requirements is that if an object of class A is declared in main, it must not compile due to not having a default constructor. So what can I do to make class B work and compile?
Another question I have is why is this valid:
Code: class A; //#include "A.h" is in the implementation file so it compiles. class B { private:A* a;}; But not this: Code: class A;
class B { private:A a;};
This is for a project that I probably won't be able to turn in on time, but I care more about how to do this right than turning it in for full points.
Here's the problem. I want to generate an array of objects from classes.
brick[] tile = new brick[5] // originally wanted an array of 500 to play with but I thought I'd start small first
I wanted to make a draw() function in my "level01" class to generate a map (so I wouldn't have to build them in photoshop then manipulate rectangle bounding boxes). I tried several things...
First, I found a thread that worked to get rid of the null value in the array ("not set to reference of an object" error).
After that, within a for loop, I tried to initiate my values...
for (int i=0; i < tile.Length; i++) { tile[i] = new brick(); // calling the object piece[i] = new PictureBox(); // calling the object's container //tile[i].brick1X = 38; // already had a default set to it so I commented this out to see if it made // any difference... it didn't tile[i].brick1Y += 32; // if this worked, it would have drawn a 32x32 tile down the Y axis every 32 // pixels
[Code] ....
In my Form.cs, I declared my first level map as: level01 L01 = new level01();
Under the form's constructor, I instructed it to L01.draw(); so that it would initiate on the game screen.
Needless to say, I get the game screen and the frame, the menu bar I have pops up. But, no tiles.
I even went so far as to get rid of the null values for [i] in the array (using the above for loop but with fewer tasks within the loop) and created a counter that would count up += 1 every time it would make an object.
if (counter < 5) {
And would put in the above tasks inside of the logic loop. I would either get nothing drawn on the screen or it would throw an exception.
I could easily make this using XNA Game Studio in Visual Studio 2010 but I'm using VS2013 and wanted to do a program straight in C# instead of using XNA.
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Drawing; using System.Windows.Forms;
The Light and Fan are two different vendor classes and they are not derived from any base class. I am trying to implement the Command design pattern but with generic implementation, so it should work in future with any new vendor class like Door, Window etc without much change in client code. I have thought about a Factory method but it will not work because it needs a Base class. I am trying to learn the design patterns.
Light *myobj; Fan *myobj; int choice; cout<<"Select Light (1): "; cout<<"Select Fan (2): ";
I have a project which does a specific thing, like an open file dialog.
I would like to open it in a different project on a click of a button.
Also, It has a different namespace.
I'm guessing that it would involve a "using" statement to add the namespace And I will have to add reference to an *.exe or *.dll -> I'll have to look up how to make a *.dll, I know where the *.exe file is.
I have searched for a different things on Google, but I don't think that I am looking for the correct phrase (which is always frustrating...)
I have an array of (Student)classes created in Manager.h, which contains a new instance of class Name (name),(in Student.h)How would I go about accessing the SetFirstName method in Name.cpp if I was in a class Manager.cpp? I have tried using Students[i].name.SetFirstName("name");
// In Manager.h #include"Student.h" class Manager {
so my program is quite simple and it works fine when i execute it but when i try to run through it with gdb i get an error. so this is what i get from gdb
Code:
Breakpoint 1, main () at fun.c:4 4 { (gdb) watch a Hardware watchpoint 2: a (gdb) next 6 a=0;b=0;c=0; (gdb) next
how to ask for the input (className) without getting stuck in the loop. When I remove
char className; cout << "Enter the class name: " << endl; cin >> className;
it works fine. When I leave it how it's displayed below it goes in an infinite loop. By the way I think "char" is not the appropriate way to declare className. If I want to output it later, should I changed it to "string"?
#include <iostream> using namespace std; int main() {
my code seems to enter an infinite loop should a user mistakenly enter a character other than a digit. The code is about selecting from a preset number of options, numbered 1- 4. If the user mistakenly enters a letter for example, instead of a number, the infinite loop kicks in...
I have a school project where I have to create a class with 2 attributes that default to 1. To verify that they are at 1, I have a cout before any user inputs or value manipulation. It works for the most part. What happens is that if I change the defaults to 17, the cout will retain the old values until I have an unsuccessful build (remove a semicolon from the end of the line). When I have a successful build (put that semicolon back), the cout displays the changed values. Change the values back to 1 and the same thing happens again until I have an unsuccessful build then a successful build. Are the old values getting stuck in memory somewhere?
// Rectangle.h // Chapter 9_Problem 9.11_Page 412 #include <iostream> using namespace std; #ifndef RECTANGLE_H #define RECTANGLE_H class Rectangle // Rectangle class { public: Rectangle(double = 17, double = 17); // default constructor setting values to 1
I want to create a loop that that generates a random number set and gives the user the option to run the loop again for a new number. I have that working but when the loop ends the variable value does not leave the loop. I tried a posttest and pretest loop.
Is it possible to declare/create/alter a variable in a loop and have that value exit the loop to use in the code later? I am still learning about global variables.
#include <iostream> #include <cstdlib> #include <ctime> #include <string> int oneDiceSix() // Roll 1d6 {int oneDiceSix = 1+(rand()%6); return oneDiceSix;} //end function
So this is my first attempt at actually writing code, I have a little basic core functionality set up and I'm 99% sure I'm doing something very fundamentally wrong with pointers.
#include <stdio.h> #include <assert.h> #include <stdlib.h> #include <string.h> struct Creature { int pow; int tou;
[code] ....
Error generated:
magic.c: In function "main": magic.c:71:26: warning: initialization from incompatible pointer type [enabled by default] struct Creaturedb *db = Initialize_creaturedb; ^ magic.c:72:22: warning: initialization from incompatible pointer type [enabled by default] struct Player *pl = Initialize_player; ^
Code: #include<stdlib.h>#include<stdio.h> #include<unistd.h> #include<math.h> int main(void) { double N, NG, LG, epsilon, root; // setting all variables to type double
[Code] .....
The goal is to create a program to calculate the square root of a number provided by the user to an error tolerance 0.005
Looking around i fond the Code: fabs(NG - LG) < epsilon); section that was very similar to what i was using, but if this is better im down for that.
My issue, from what i can see, is the updating of the values of LG. if the test for error tolerance fails then LG needs to take on the value of the results of NG.
Now I am not 100% that is the point of failure due to the fact the script does calculate the root properly, but it never exits the program once it reaches the tolerance level.
Code: imac:ENG-3211 user$ ./hw_4_1
Please enter the number you wish to find the square root: 4
I currently have a hangman game in the making. Which is giving me debugging issues when I go to pick a letter, it will keep asking for a letter, if I place a break; within the loop it asks for a letter and says you've won. I know all I should need is a couple extra lines somewhere within the code.
/// Play game public static string playGame() { Words words = new Words();
I've written some code to randomly generate probabilities:
int Queue::car_per_hr() { srand( time( NULL )); int prob = rand() % + 101; // Probability in percentage from 0 to 100 int cars; //no of cars per hr
[Code] ....
So it checks through the range of possibilities: 0-20%, 21-40% etc. I then have this to implement it:
#include <iostream> #include <ctime> #include "queue.h" using namespace std; int main(){ Queue car_wash; int NO_HOURS;
[Code] .....
For some reason though, everytime I call the car_per_hr() function, the probability just stays the same. It's output is always locked to the same thing it had to begin with?
Here is my code and everything works except i can not get the highest array number to be output. it always says 10.
My instructions are:
(1) Create a 10-integer array called data (2) Set a pointer ptr to point to array data (3) Output the elements in array data using pointer ptr (4) Find the largest element in the array data using pointer ptr
#include <iostream> #include <cstdlib> using namespace std;
I'm having trouble getting my loop to work correctly. If I iterate the for loop once it works as expected and displays proper output. When I try to iterate two times or more the program gets stuck in an infinite loop.
I am making a math game program that simple and need to have a user input a name and then that name.txt is brought up and use variables from the text to add to their score. heres my code kinda long.
