Random Number Generator Program...PLEASE HELP!!

Hi all,

This is my first experience with c++ programming. I am struggling with our first assignment to create a program that generates 10 random numbers. We are supposed to separate the implementation and the interface, so I have a header file (rng.h) and 2 cpp files (rng.cpp, main. cpp). Can someone please help me out?? I'm not even sure if I'm on the right track and I'm getting 5 errors when I compile.

Any help is GREATLY appreciated.

Thanks in advance.

rng.h

Code:

---

#ifndef RNG_H
#define RHG_H

//aRandomNumberGenerator class definition
class aRandomNumberGenerator
{
public:
    //Constructor initializes aRandomNumberGenerator
    aRandomNumberGenerator();
    void setSeed(unsigned long);
    double generate();
       
private:
    unsigned long seed;
}; //end of class aRandomNumberGenerator

#endif

---

rng.cpp

Code:

---

#include <iostream>
#include <cstdlib>
#include "rng.h"

using namespace std;

void aRandomNumberGenerator::setSeed(unsigned long)
{
        seed = 2345;
        srand(seed);
}

double aRandomNumberGenerator::generate()
{
        return rand();
}

---

main.c

Code:

---

#include <iostream>
#include <cstdlib>

#include "rng.h"
#include "rng.cpp"

int main()
{
        cout<<"Ten random numbers are: "<<endl;

        for(double i = 0; i<=10; i++)
        {
                cout<<generate();
        }
        return 0;
}

---

main.c , you might need to use namespace std.. as in

Code:

---

using namespace std;

---

when you use generate() , you need to make an object of arandomnumbergenerator first, since you made it so its in a class

Code:

---

aRandomNumberGenerator myrng;
cout << myrng.generate(); // like this

---

click here for more help

Quote:

---

Originally Posted by girly_engineer

I'm getting 5 errors when I compile.

---

The exact number of errors you are getting is not as useful for us as the actual errors themselves are. You may not be able to understand them, but we certainly can, so post em!

I can't speak for everyone but I almost never bother creating a blank project and copy and pasting your code in, and then compiling it. If you're using a different compiler you might get some different errors anyway, so we need to see your compilation errors!

Code:

---

#include <iostream>
#include <math.h>
#include <time.h>
#include "numbergenerator.h"//what i named header file

using namespace std;

int main()
{
   
    random generate;
   
   
    srand(time(NULL));
    for (int loopNumber = 0; loopNumber < 10; loopNumber++)
    {
        int randomNumber = generate.generateRandomNumber();
        cout << randomNumber << endl;
    }
    cin.get();
   
}

---

Header file contents:

Code:

---

class random {
      public:
            int generateRandomNumber()
            {                 
                return rand();
                                                       
            }
};

---

yeah so im a noob so there may be problems with this... all i know is that it works

Also cross-posted here

Ok these are the errors I am currently getting.

1>------ Build started: Project: Project 1, Configuration: Debug Win32 ------
1>Compiling...
1>rng.cpp
1>main.cpp
1>t:\remydoc\logu17\visual studio 2008\projects\project 1\project 1\rng.h(6) : error C2011: 'aRandomNumberGenerator' : 'class' type redefinition
1> t:\remydoc\logu17\visual studio 2008\projects\project 1\project 1\rng.h(6) : see declaration of 'aRandomNumberGenerator'
1>t:\remydoc\logu17\visual studio 2008\projects\project 1\project 1\rng.cpp(7) : error C2027: use of undefined type 'aRandomNumberGenerator'
1> t:\remydoc\logu17\visual studio 2008\projects\project 1\project 1\rng.h(6) : see declaration of 'aRandomNumberGenerator'
1>t:\remydoc\logu17\visual studio 2008\projects\project 1\project 1\rng.cpp(13) : error C2027: use of undefined type 'aRandomNumberGenerator'
1> t:\remydoc\logu17\visual studio 2008\projects\project 1\project 1\rng.h(6) : see declaration of 'aRandomNumberGenerator'
1>Generating Code...
1>Build log was saved at "file://t:\ReMyDoc\logu17\Visual Studio 2008\Projects\Project 1\Project 1\Debug\BuildLog.htm"
1>Project 1 - 3 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

These are the files I'm compiling with changes

rng.h

Code:

---

#ifndef RNG_H
#define RHG_H

//aRandomNumberGenerator class definition
class aRandomNumberGenerator
{
public:
    //Constructor initializes aRandomNumberGenerator
    aRandomNumberGenerator();
    void setSeed(unsigned long);
    double generate();
       
private:
    unsigned long seed;
}; //end of class aRandomNumberGenerator

#endif

---

rng.cpp

Code:

---

#include <iostream>
#include <cstdlib>
#include "rng.h"

using namespace std;

void aRandomNumberGenerator::setSeed(unsigned long)
{
        int seed = 2345;
        srand(seed);
}

double aRandomNumberGenerator::generate()
{
        double r = rand();
        return r;
}

---

main.cpp

Code:

---

#include <iostream>
#include <cstdlib>

#include "rng.h"
#include "rng.cpp"

using namespace std;

int main()
{
       
        cout<<"Ten random numbers are: "<<endl;

        for(int i = 0; i<=10; i++)
        {
                cout<<generate() ;
        }
        return 0;
}

---

I think you are getting the first error,
C2011: 'aRandomNumberGenerator' : 'class' type redefinition

because you the way main.cpp is included rng.h and rng.cpp. Even though you have the header guard set up in rng.h, I think the compiler is trying to include it twice...once from the include rng.h in main.cpp and coming over with rng.cpp as well. Hope this makes sense.

Try removing the include for rng.h from main.cpp and see if that will get your further.

Ok so I revised my code and now I'm getting one error:

1>------ Build started: Project: Project 1, Configuration: Debug Win32 ------
1>Compiling...
1>main.cpp
1>t:\remydoc\logu17\visual studio 2008\projects\project 1\project 1\main.cpp(16) : error C2660: 'aRandomNumberGenerator::setSeed' : function does not take 0 arguments
1>Build log was saved at "file://t:\ReMyDoc\logu17\Visual Studio 2008\Projects\Project 1\Project 1\Debug\BuildLog.htm"
1>Project 1 - 1 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

rng. h

Code:

---

#ifndef RNG_H
#define RHG_H

//aRandomNumberGenerator class definition
class aRandomNumberGenerator
{
public:
    //Constructor initializes aRandomNumberGenerator
    aRandomNumberGenerator();
    void setSeed(unsigned long);
    double generate();
       
private:
    unsigned long seed;
}; //end of class aRandomNumberGenerator

#endif

---

rng.cpp

Code:

---

#include <iostream>
#include <cstdlib>
#include "rng.h"

using namespace std;

void aRandomNumberGenerator::setSeed(unsigned long)
{
        int seed = 2345;
        srand(seed);
}

double aRandomNumberGenerator::generate()
{
       
        for(int i = 0; i<=10; i++)
        {
                double r = rand();
                return r;
                cout<<r ;
        }
       
}

---

main.cpp

Code:

---

#include <iostream>
#include <cstdlib>


#include "rng.h"

using namespace std;

int main()
{
       
        cout<<"Ten random numbers are: "<<endl;
       
        aRandomNumberGenerator rand;

        rand.setSeed();
        rand.generate();
       
}

---

You need to pass something to your setSeed() function...you have it defined as
void aRandomNumberGenerator::setSeed(unsigned long) in rng.cpp. Something like this in main.cpp

rand.setSeed(1);

When I pass a value to setSeed I get this error:

1>------ Build started: Project: Project 1, Configuration: Debug Win32 ------
1>Compiling...
1>main.cpp
1>Linking...
1>main.obj : error LNK2019: unresolved external symbol "public: __thiscall aRandomNumberGenerator::aRandomNumberGenerator(voi d)" (??0aRandomNumberGenerator@@QAE@XZ) referenced in function _main
1>t:\ReMyDoc\logu17\Visual Studio 2008\Projects\Project 1\Debug\Project 1.exe : fatal error LNK1120: 1 unresolved externals
1>Build log was saved at "file://t:\ReMyDoc\logu17\Visual Studio 2008\Projects\Project 1\Project 1\Debug\BuildLog.htm"
1>Project 1 - 2 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Add a constructor call in rng.cpp after

Code:

---

using namespace std;

aRandomNumberGenerator::aRandomNumberGenerator() {
       
}

---

Ok I'm trying this, but still getting an error:

Code:

---

aRandomNumberGenerator::aRandomNumberGenerator()
{
        setSeed();
}

---

I actually got your first source code post to work with a few modifications. First was to add a constructor call to rng.cpp ( aRandomNumberGenerator::aRandomNumberGenerator() ), second was to remove the include of rng.h in main.cpp and I also added an endl to your print out of the random numbers for readability...the following code compiled for me using the g++ compiler on a CentOS 5.4 machine.

rng.h

Code:

---

#ifndef RNG_H
#define RHG_H

//aRandomNumberGenerator class definition
class aRandomNumberGenerator {
public:
    //Constructor initializes aRandomNumberGenerator
    aRandomNumberGenerator();
    void setSeed(unsigned long);
    double generate();
       
private:
    unsigned long seed;
}; //end of class aRandomNumberGenerator

#endif

---

rng.cpp

Code:

---

#include <iostream>
#include <cstdlib>
#include "rng.h"

aRandomNumberGenerator::aRandomNumberGenerator() {
       
}

void aRandomNumberGenerator::setSeed(unsigned long)
{
        seed = 2345;
        srand(seed);
}

double aRandomNumberGenerator::generate()
{
        return rand();
}

---

main.cpp

Code:

---

#include <iostream>
#include <cstdlib>

#include "rng.cpp"

using namespace std;

int main(void) {

        aRandomNumberGenerator myrng;
       
        cout << "Ten random numbers are: " << endl;

        for(double i = 0; i<=10; i++) {
                cout << myrng.generate() << endl;
        }

        return 0;
}

---

I'm using Visual Studio 2008 and I got errors when I ran the code in the post above.

So, what are the errors?

These are the errors I get using Visual Studio

1>------ Build started: Project: DEMO2, Configuration: Debug Win32 ------
1>Compiling...
1>rng.cpp
1>main.cpp
1>Generating Code...
1>Compiling manifest to resources...
1>Microsoft (R) Windows (R) Resource Compiler Version 6.1.6723.1
1>Copyright (C) Microsoft Corporation. All rights reserved.
1>Linking...
1>main.obj : error LNK2005: "public: __thiscall aRandomNumberGenerator::aRandomNumberGenerator(voi d)" (??0aRandomNumberGenerator@@QAE@XZ) already defined in rng.obj
1>main.obj : error LNK2005: "public: void __thiscall aRandomNumberGenerator::setSeed(unsigned long)" (?setSeed@aRandomNumberGenerator@@QAEXK@Z) already defined in rng.obj
1>main.obj : error LNK2005: "public: double __thiscall aRandomNumberGenerator::generate(void)" (?generate@aRandomNumberGenerator@@QAENXZ) already defined in rng.obj
1>C:\Users\Neesha\Documents\Visual Studio 2008\Projects\DEMO2\Debug\DEMO2.exe : fatal error LNK1169: one or more multiply defined symbols found
1>Build log was saved at "file://c:\Users\Neesha\Documents\Visual Studio 2008\Projects\DEMO2\Debug\BuildLog.htm"
1>DEMO2 - 4 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

I fixed the errors and my program works now :)

THANKS FOR ALL THE HELP!!!!!

Quote:

---

Originally Posted by girly_engineer

I fixed the errors and my program works now :)

THANKS FOR ALL THE HELP!!!!!

---

The code might seem to be working now but be aware that there are a couple of things your teacher might frown upon in the code that Skreaminskull gave you:

First of all, don't ever include a .cpp file, it's wrong, we only include .h or .hpp files, never .cpp!

Second of all, the code never calls the setseed() function, so the number will not be random at all.

Third of all, your setseed() function doesn't utilize the unsigned int parameter that you gave it, it just uses some magic number which is not only a poor way of coding, it also looks unfinished, as if you wrote the code to test the functionality and then never finished it?