Creating a Derived Class in C++ -

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• why have header files , .cpp files? [closed] 9 answers

so im trying make die class , loadeddie class die class base , loadeddie class derived. difference between 2 classes roll function in loadeddie has 25% chance of getting highest number, whereas die, has 1/6 chance. 1st time working derived class , seem have quite problem trying complete task. can explain me how works , show me how classes (as im visual learner , need examples). know base class (die) works tested out before moving loadeddie.

die.cpp

#include<iostream> #include <cstdlib> using namespace std;  class die{     public:         die();         die(int numside);         virtual int roll() const;         int rolltwodice(die d1, die d2);          int side; };  die::die():side(6){}  die::die(int numside):side(numside){}  int die::roll() const{     return rand() % side + 1; }  int die::rolltwodice(die d1, die d2){     return d1.roll()+d2.roll(); } 

loadeddie.cpp

#include<iostream> #include <cstdlib> #include "die.cpp" using namespace std;  class loadeddie: public die{     public:         loadeddie();         loadeddie(int numside);         virtual int loadedroll() const; };  loadeddie::loadeddie():side(6){}  loadeddie::loadeddie(int numside):side(numside){}  int loadeddie::loadedroll() const{     if ((rand() % 2)+1) = 1){         return side;         }     return (rand() % (side-1)) + 1; }  int loadeddie::rolltwodice(loadeddie d1, loadeddie d2){     return d1.roll()+d2.roll(); } 

my dietester.cpp (just main class test if above classes work):

#include "loadeddie.cpp" #include<iostream> #include<time.h> #include <stdlib.h>  using namespace std;  int main(){      srand(time(null));        die d(6);     loadeddie dl(6);     cout << d.roll()<<endl;     cout<<"ld " << dl.roll()<<endl; } 

with classes above, error when run dietester.cpp (if helps):

in file included dietester.cpp:1: loadeddie.cpp: in constructor ‘loadeddie::loadeddie()’: loadeddie.cpp:13: error: class ‘loadeddie’ not have field named ‘side’ loadeddie.cpp: in constructor ‘loadeddie::loadeddie(int)’: loadeddie.cpp:15: error: class ‘loadeddie’ not have field named ‘side’ loadeddie.cpp: in member function ‘virtual int loadeddie::loadedroll() const’: loadeddie.cpp:18: error: expected primary-expression before ‘=’ token loadeddie.cpp:18: error: expected ‘;’ before ‘)’ token 

i believe these errors due me not deriving classes properly. can explain me how done?

it's bad form #include cpp files. if want it, rid of #include "die.cpp" statement in main.cpp. it's included in loadeddie.cpp , including twice , defining twice--hence 'redefinition' error.